You are a member of an alpine rescue team and must get a box of supplies, with mass 3 kg , up an incline of constant slope angle 30.0, so that it reaches a stranded skier who is a vertical distance 4 m above the bottom of the incline. There is some friction present; the kinetic coefficient of friction is 0.05. Since you can't walk up the incline, you give the box a push that gives it an initial velocity; then the box slides up the incline, slowing down under the forces of friction and gravity. Take acceleration due to gravity to be 9.81 m/s2 .What is the minimum speed v that you must give the box at the bottom of the incline so that it will reach the skier

Answers

Answer 1

Answer:

v = 9.04 m / s

Explanation:

For this exercise we can use the relation that the work of the non-conservative force (friction) is equal to the variation of the mechanical energy of the system.

          W = Em_f - Em₀         (1)

Starting point. Lower slope

        Em₀ = K = ½ m v²

highest point. Where is the skier at a height h

        Em_f = U = m g h

The work of rubbing

        W = -fr x

the negative sign is because the friction force opposes the movement.

Let's set a reference system where the x axis is parallel to the slope and the y axis is perpendicular

let's use trigonometry to break down the weight

        cos θ = W_y / W

        sin θ = Wₓ / W

        W_y = W cos θ

        Wₓ = W sin θ

Y axis

        N - Wₓ = 0

        N = mg sin  θ

X axis

         fr = m a

the friction force has the expression

         fr = μ N

         fr = μ mg sin θ

we look for the job

         W = - μ mg sin θ  x

where x is the distance along the slope

       

we substitute in 1

         -μ mg sin θ x = mg h - ½ m v²

let's use trigonometry to find the distance x

        tan 30 = h / x

        x = h / tan 30

we substitute

          -   [tex]\mu \ mg \ sin \theta \ \frac{h}{tan 30} \ x[/tex] = m gh - ½ m v²

we use  

          tan 30 = sin30 / cos30

         

          v² = 2g h + 2 μ g h cos 30

          v = [tex]\sqrt{ 2gh \ (1+ cos 30}[/tex]

let's calculate

          v = [tex]\sqrt{ 2 \ 9.8 \ 4 \ (1 + 0.05 \ cos \ 30)}[/tex]

          v = 9.04 m / s


Related Questions

If the delay of the 10-bit adder is 1ns, the setup time, the hold time, and the propagation delay of the registers is 0.3 ns, 0.1 ns, and 0.2 ns, respectively. The minimum cycle time is ns_____.

Answers

Answer:

1.6 ns

Explanation:

Given data :

delay in 10-bit adder = 1ns

setup time = 0.3 ns

hold time = 0.1 ns

propagation delay = 0.2 ns

calculate the minimum cycle time

∑ delay + setup time + hold time + propagation delay

= 1 + 0.3 + 0.1 + 0.2

= 1.6 ns

Select the correct answer.
Which theory was first proposed by Albert Einstein?
OA. the theory of special relativity
O B. the theory of universal gravitation
c. the theory of inertia
OD. the theory of radioactivity

Answers

Answer:

A. the theory of special relativity.

Explanation:

The theory of special relativity was first proposed theory by Albert Einstein.

Hope it will help :)❤

A the special of relativity

Please Help!!!!!
Belinda observes that the reaction 2H2O+O2=2H2O2 appears to have stopped, because the concentrations of reactants and products are not changing. Which statement is true at this point in the reaction
A P E X

Answers

Answer: Molecules of H202, H20 and 02 are still forming. ( A P E X )

Explanation: I know this is late but for anyone looking at this later

The above question is incomplete, I think the original  question is

Belinda observes that the reaction 2H20+02 2H2O2 appears to have stopped because the concentrations of reactants and products are not changing. Which statement is true at this point in the reaction?

A. Molecules of H₂O₂ are formed only when the reaction vessel is disturbed.

B. Molecules of H2O2 have stopped forming.

C. Molecules of H20 and O₂ have stopped forming.

D. Molecules of H2O2, H2O, and O2 are still forming.

At this point in the reaction, the system has reached a state of equilibrium i.e there is no net change in the concentrations of reactants and products. So the Molecules of H2O2 have stopped forming. The correct option is B.

What is the state of equilibrium?

In chemistry, a state of equilibrium refers to a situation where the concentrations of reactants and products in a chemical reaction are no longer changing over time.

This occurs when the rates of the forward and reverse reactions are equal, and there is no net change in the concentrations of reactants and products.

At equilibrium, the system is in a dynamic state, where the forward and reverse reactions continue to occur, but at the same rate, resulting in no overall change in the concentrations of the species involved in the reaction. The equilibrium state is typically characterized by the equilibrium constant, which is a measure of the relative concentrations of reactants and products at equilibrium for a given reaction under specific conditions of temperature, pressure, and concentration.

Here in this question,

The molecules of H2O2 have stopped forming. This means that the forward reaction (2H2O + O2 → 2H2O2) and the reverse reaction (2H2O2 → 2H2O + O2) are occurring at the same rate, resulting in no net change in the concentration of H2O2. However, molecules of H2O and O2 are still being consumed and produced as they are involved in the reaction, but their concentrations are not changing because they are being replenished at the same rate that they are being consumed.

Therefore, the correct answer is B i.e Molecules of H2O2 have stopped forming.

To learn about redox reactions click:

https://brainly.com/question/13293425

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Why is the answer (A)?
In details please​

Answers

Explanation:

resistance of wire can be determined by this equation

R = Rho . L / A

L = the length of wire

A = the Area, A = πr²

Rho = density of resictance

we can do some rational

R1/R2 = ( Rho L1/A1) / (Rho L2/A2)

L2 is the condition when the length is doubled and

L2 = 2 x L

A2 is the condition when the diameter is doubled

A2 = 4A1

R/R2 = (L1/A1)/(L2/A2)

R/R2 = (L/A) / (2L/4A)

R/R2 = 1 / ½

R2 = ½ R.

then we use formula of Voltage

V = I R

1st condition

V = 0.3 R

2nd condition ( V is constant)

V = I2 R2

0.3 R = I2 x ½R

i2 = 0.3/ ½

i2 = 0.6 Ampere

Which of the following involves an endothermic reaction

Answers

Answer:

A

Explanation:

Photosynthesis requires energy to drive the chemical reaction. Photosynthesis is an endothermic reaction. This means it cannot occur without energy (from the Sun).

I need help! thank you

Answers

Answer:

it is coice A and choice D

A town requiring 2.0 m3/s of drinking water has two sources, a local well with 15 g/m3 nitrate (as N) and a distant reservoir with 5 g/m3 nitrate (as N). What flow rates of well and reservoir water are needed to meet the EPA drinking water standard and minimize the use of more expensive reservoir water

Answers

Explanation:

Drinking water requirement in town 2.0 m^3/s of water per second

nitrate in local well  nitrate per 15 [tex]\mathrm{m}^{3}[/tex] of water

nitrate in distant reservoir [tex]=5 \mathrm{~g} / \mathrm{m}^{3}[/tex]

Let the flow rate of well

flow rate of reservoir [tex]=y m^{3} / s[/tex]

Drinking water requirement is [tex]45 \mathrm{ppm}[/tex] or [tex]45 \mathrm{~g} / \mathrm{m}^{3}[/tex]

therefore, the total flow of drinking water

 

A sinusoidal wave is reflected at the surface of a medium whose properties are such that half the incident energy is absorbed. Consider the field that results from the superposition of the incident and the reflected wave. An observer stationed somewhere in this field finds the local electric field oscillating with a certain amplitude E. What is the ratio of the largest such amplitude noted by an observer to the smallest amplitude noted by any observer

Answers

Answer:

[tex]\frac{Ei + Er}{Ei-Er}[/tex]

Explanation:

Ratio of the largest amplitude to the smallest amplitude is called voltage standing wave ratio ( along a transmission line )

Determine the ratio of the largest such amplitude noted by an observer tot the smallest amplitude

Expression for VSWR

VSWR =  [tex]\frac{1 + \sqrt{\frac{Pr}{Pi} } }{1 - \sqrt{\frac{Pr}{Pi} } }[/tex]    where ; Pr = reflected power , Pi = Incident power

hence the ratio of the largest amplitude to the smallest amplitude

= [tex]\frac{Emax}{Emin}[/tex] = [tex]\frac{Ei + Er}{Ei-Er}[/tex]  where ; Ei = amplitude of incident wave, Er = amplitude of reflected wave

How much resistance is required to limit the current from a 12 V battery to 3.6 mA?

Answers

Answer:

3333.3 ohm

Explanation:

V=IR so R =V/I (in Ampere) so convert 3.6 mA to 3.6*10^-3 A

so R =12/3.6*10^-3 =3333.3

The diagram below shows the beaks of five species of birds that developed over time from
one parent species. The five species of birds can be found living in the different areas. Which
of the following BEST explains why the beak shape of each species of bird developed
differently? * 5
(1 Point)
A. Birds in different areas were able to make different birdcalls and songs.
O
B. Birds in different areas were exposed to different food sources.
C. Birds in different areas had different materials to make nests.
o o
D. Birds in different areas had different predators to defend or hide from.

Answers

Answer:

Birds in different areas were exposed to different food sources.

Explanation:Im almost 100 percent this is it.

Answer:

the answer is B

Explanation:

i did test on preformance

Why are some areas in Europe seeing a partial solar eclipse while others are observing a total solar eclipse?

plz answer ASAP

Answers

Answer:

Objects between the source and observer produce possible shadows known as the umbra and the penumbra.

The umbra is a totally shadowed area, no light travels directly from the source to the observer.

The penumbra is a partially shadowed are where some of the source light travels directly to the observer an some of the source light is blocked from the observer (the object blocking the light is not a point object).

The question apparently refers to the differences seen by the observers.

A submarine is 309 m horizontally from the shore of a freshwater lake and 105 m beneath the surface of the water. A laser beam is sent from the submarine so that the beam strikes the surface of the water 227 m from the shore. A building stands on the shore, and the laser beam hits a target at the top of the building. The goal is to find the height of the target above sea level.

Required:
a. Draw a diagram of the situation, Identifying the two triangles that are important in finding the solution.
b. Find the angle of incidence of the beam striking the water-air interface.
c. Find the angle of refraction.
d. What angle does the refracted beam make with the horizontal?
e. Find the height of the target above sea level.

Answers

Answer:

Explanation:

a) See the attached file for diagram . The two triangles are ABC and DEC .

b )

Angle of incidence = i

Tan i = ( 309 - 227 ) / 105

= 82 / 105 = .78

i = 38°

c )

Sin i / sinr = 1 / μ where μ is refractive index of water .

Sin i / sinr = 1 / μ = 1 / 1.33

sin 38 / sinr = .7518

.6156 / sinr = .7518

sinr = .6156 / .7518

.819

r = 55°

d )

angle  the refracted beam makes with the horizontal = 90 - 55 = 35°

e )

h / 227 = Tan 35

h = 227 x Tan 35

= 159 m

Height required = 159 m .

What happened to the pod during those seconds when communication was lost?

Answers

Answer:

Explanation:

From our investigation of what forces are like in a collision, we learned that when two

objects collide, a force is exerted on each object. The two forces are in opposite

directions but the same strength. This allowed us to infer that an equal strength force

was exerted on the space station and the pod, but in opposite directions.

As a result, the space station and the pod are moving in opposite directions. We need to

learn more about the effects of collisions on each object’s motion so we can report back

to Dr. Gonzales at the space agency.

You will use physical materials to gather data about

forces in a collision. You will also notice how objects

are affected by collisions. Students will use their

data to infer the force direction for objects in a

collision.

Based on the velocity change of each object,

what did you infer about the direction of forces

during a collision?

• We observed that the velocity of each object changed during a collision, so we can infer

that a force had to be exerted on each object. However, the motion of the objects

changed in different ways.

• The object that was moving forward slowed down, so I can infer that the force must have

pushed backward on this object.

• The other object started moving forward, so the force must have pushed forward on that

object. If one force was backward and one force was forward, then the forces pushed

the objects in opposite directions.

Check out this app! It's millions of students helping each other get through their schoolwork. https://brainly.app.link/qpzV02MawO​

Answers

Answer:

OK we appreciate your concern.

is this correct and why​

Answers

Answer:

correct ooooooooooooo

ANSWER THIS! Which of these statements about the Sun is the result of its closeness to Earth? A) It is the only star with a gravitational pull. B) It is the largest star in the Milky Way Galaxy. C) It appears (from Earth) to be the brightest star. D) It has the lowest temperature of any star seen from Earth.

Answers

Answer:

C) It appears (from Earth) to be the brightest star.

Explanation:

This is because due to sun's brightness we can predict its distance.

PLZZZ HELP!!! 80PTS!!!
You are given a toy car and told it has a density of 0.54 g/mL and a volume of 38.2 mL. Calculate impulse, given that the toy car's acceleration is 10 m/s^2 and time is 10 s. WRITE THE NUMBER ONLY and DO NOT ROUND.

Answers

Answer:

Impulse = [tex]206.28 * 10 = 2062.8[/tex] g.m/s

Explanation:

Impulse is equal to the product of force and time

Here

Density of car =  [tex]0.54[/tex]  g/mL

Volume of car [tex]= 38.2[/tex] mL

Mass of the car is equal to the product of density and volume of car

Mass of the car [tex]= 0.54 * 38.2[/tex] [tex]= 20.628[/tex] grams

Acceleration of the car is [tex]10[/tex] m/s^2

Force is equal to product of mass and acceleration

F = [tex]20.628 * 10 = 206.28[/tex] g .m/s^2

Impulse = F * t

Impulse = [tex]206.28 * 10 = 2062.8[/tex] g.m/s

A 1500 kg car traveling at 30 m/s hits a stationary 1200 kg car. If they stick together on collision, what is the final velocity of the two cars?

Answers

Answer:

16.67 m/s

Explanation:

Let that velocity be v.

Using conservation of momentum:

Initial momentum = final momentum

momentum of car1 = momentum of cars

mass1 x velocity1 = (m1 + m2)v

1500*30 = (1500 + 1200)v

45000/2700 = v

16.67 m/s = v

a mid-oceanic might be compared to what continental landform

Answers

Answer:

mountain range:)

Explanation:

What are some possible injuries that can occur as a result of anabolic steroid use?

Answers

Most data on the long-term effects of anabolic steroids in humans come from case reports rather than formal epidemiological studies. Serious and life-threatening adverse effects may be underreported, especially since they may occur many years later. One review found 19 deaths in published case reports related to anabolic steroid use between 1990 and 2012; however, many steroid users also used other drugs, making it difficult to show that the anabolic steroid use caused these deaths.39 One animal study found that exposing male mice for one fifth of their lifespan to steroid doses comparable to those taken by human athletes caused a high frequency of early deaths
high blood pressure, blood clots, heart attacks, stroke, artery damage, peliosis hepatis tumors, short stature (if taken by adolescents),tendon injury, aggression,
mania, delusions, severe acne and cysts, oily scalp and skin,abscess at injection site and jaundice. In men: decreased sperm production, enlarged breasts,shrinking of the testicles
male-pattern baldness, testicular cancer. In female: voice deepening,decreased breast size,coarse skin,excessive body hair growth, male-pattern baldness.

What two things can change when an object accelerates?​

Answers

Answer:

speed and velocity or direction.

I need help with science o.o:

Question 1:

An egg yolk is unicellular.

True
False
___________________________

Question 2:

Your body has more than a billion cells.

True
False
_____________________


Question 3:


Almost all cells are not microscopic.

True
False

please dont steal my points :>

Answers

Answer:

TrueTrueFalse

Explanation:

this is the answer

Answer:

1.true

2true

3.false

Explanation:

espero que te ayude

A car's bumper is designed to withstand a 7.20 km/h (2.0 m/s) collision with an immovable object without damage to the body of the car. The bumper cushions the shock by absorbing the force over a distance. Calculate the magnitude of the average force (in N) on a bumper that collapses 0.195 m while bringing a 830 kg car to rest from an initial speed of 2.0 m/s.

Answers

Answer:

8512 N

Explanation:

From the work energy theorem we know that: The net work done on a particle equals the change in the particles kinetic energy:

[tex]W=\Delta K=K_{f}-K_{i} \\ \\qquad \begin{array}{r} W=F \cdot d, \Delta K=\frac{1}{2} m v_{f}^{2}-\frac{1}{2} m v_{i}^{2} \\ F \cdot d=\frac{1}{2} m v_{f}^{2}-\frac{1}{2} m v_{i}^{2}[/tex]

Where:

-W is the work done by the force.

- F is the force actin on the.

- d is the distance travelled.

- m is the mass of the car.

- [tex]v_{f}, v_{i}[/tex] are the final and the initial velocity of the car

[tex]K_{f}, K_{i}[/tex] are the final and the kinetic energy of the car.

Givens: [tex]m=830 \mathrm{~kg}, v_{i}=2 \mathrm{~m} / \mathrm{s}, v_{f}=0 \mathrm{~km} / \mathrm{h}, d=0.195 \mathrm{~m}[/tex]

Plugging known information to get:

[tex]F \cdot d &=\frac{1}{2} m v_{f}^{2}-\frac{1}{2} m v_{i}^{2} \\ F &=\frac{\frac{1}{2} m v_{f}^{2}-\frac{1}{2} m v_{i}^{2}}{d} \\ &=\frac{0-\frac{1}{2} \times 830 \times 2^{2}}{0.195} \\ &=8.512 \times 10^{3} \\ F &=8.512 \times 10^{3} \mathrm{~N}[/tex]

What is the legal BAC for teens in the state of California?

Answers

Underage drivers (motorists who are under the age of 21) who operate a vehicle while “under the influence” or with a blood alcohol concentration (BAC) of . 08% or higher can be charged with a “standard” DUI and generally face the same penalties as drivers who are at least 21 years old.

Need this homework for today so help 50 point

Answers

Number one- the pendelum slowly reduces energy and eventually loses everything and will stand still.
Number two- I can account due to the factor of it repeating the same result

In Bohr's model, the position of the electron (with the monochromatic light on)... Group of answer choices is restricted to orbits or certain radii, but the electron may be observed between these orbits when it moves. is restricted to orbits of certain radii around the nucleus. The position may change, but it must be in one of these orbits. is not constrained. The electron may be found anywhere outside of the nucleus.

Answers

Answer:

True.  it is restricted to the orbits of certain radii around the nucleus.

The position can change, but it must be in one of these orbits

Explanation:

In this exercise some affirmations are given and you must select which ones are correct, for this we review the Bohr atomic model that has the following postulates:

* the orbits are circular

* Only certain orbits are stable, stationary state

* the radiation emitted is the difference in energy between two stable orbits

* the size of the orbit is given by the quantization of the angular momentum

             L = n [tex]\hbar[/tex]

When reviewing the different statements, the correct one is:

* it is restricted to the orbits of certain radii around the nucleus.

The position can change, but it must be in one of these orbits

Need help ASAP on number 4 pls

Answers

The Arrows on both sides that has equal length is wrong and the rest of the boxes are the correct

A thermionic tube with only a cathode and an anode is called?​

Answers

A vacuum tube consists of cathode (also called as filament), anode (also called as plate), and electrode (also called as grid). Cathode is an electron emitter that emits the free electrons whereas anode is an electron collector that collects the free electrons.
I hope this helps.
The correct answer is diode.

describe the relationship of the atoms shown above
choices:

Answers

Answer:

I don't know.

Background information:
We know that power is the rate that work is done; what that
really means is that power tells up how much work is done every
second. To calculate power we just divide the amount of work that
was done by the time it took to do it (Power=work/time). Work is
measured in Joules and time is measured in seconds, we end up with Joules/sec when we calculate power. A Joule/sec is a Watt; we’ll use Watts to measure and compare power.
We also know that the work done on an object is the amount of energy it has gained. For this activity, you’ll be raising your body up as you do pushups which means you’ll be giving your body gravitational potential energy (GPE). To calculate the amount of GPE we multiply mass time gravity times the height raised (GPE=mgh).
What to do (record everything in the table):
1. You need to have a decent estimate of your mass in kilograms: On earth, every
kilogram weighs 2.2 pounds. Either measure your weight on a scale or just
estimate it (in pounds) then divide by 2.2 to get your mass in kilograms.
2. Measure or estimate the length of your upper arm from your elbow to your
shoulder in centimeters...this is how high you raise yourself for every pushup.
3. Decide if you’ll do regular pushups (on your toes) or simpler pushups (knees). If
you are doing regular pushups, multiply your mass by 0.68 because you’ll only be lifting about 68% of your mass each time; if you’re doing simpler pushups, multiply your mass by 0.52 because you’ll only be lifting about 52% of your mass each time.
4. Measure the time it takes for you to do 10 pushups.

Answers

Answer:

Power is the rate at which work is done. It is the work/time ratio. Mathematically, it is computed using the following equation. The standard metric unit of power is the Watt.

Explanation:

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After being persecuted for their different religious beliefs in the East, the Mormons moved west to establish a new community. Where did they settle? A. Las Vegas, Nevada B. Cheyenne, Wyoming C. Salt Lake City, Utah D. Denver, Colorado A store is having a sale on trail mix and jellybeans for 3 pounds of trail mix and 5 pounds of jellybeans the total cost is $23 for 6 pounds of trail mix and 2 pounds of jellybeans the cost is $20 find the cost for each pound of trail mix in each pan of jellybeans h + 86.43 = 531.79h = ___________ Learning involves changes in an individual's behavior resulting from previous experiences and information.t or f I really need help with this!! If you know how to solve please help!Find the sum of sides of a convex polygon if the sum of the measures of its interior angles is: 540 degrees, 1080 degrees, 1800 degrees, 1620 degrees, 2340 degrees, 3600 degrees, 2880 degrees, and 7560 degrees. 16,000 grow 3% each year Venus Fly trap is a great example of which type of tropism? a Thigmotropism bGravitropism cPhototropism dHydrotropism Julie buys 3 kg of apples and 5 kg of pears for 12.20. The pears cost 1.60 per kilogram. What is the price per kilogram.What is the price per kilogram of the apples?You must show your working ou. What operation should you perform first when you evaluate this expression? 85 + (9 - 25 x 5) 3 *Answers:85 + 99-2525 x 585 3 If f(x) = , g(x) = 5x, and h(x) = x + 4, find each value. h[f(4)], g[h(2)], f[g(1)]. pls write the steps. DON'T SEND A LINK OR FILE! please help times running out An object wants to maintain its state of motion because it has mass.another true or false When finding the probability of getting a heads when flipping a coin. Which of the following should produce an experimental probability closest to the theoreticalprobability? The image, in which A represents a gene, shows a harmless mutation that has occurred in a species' genome. Which is the mostplausible way that this mutation may eventually benefit the species?A)Multiple copies of genes increase gene expression and protein synthesis,improving fitnessB) One copy of the gene may mutate further and begin to function differentlyfrom the original.C) Individuals with different copy numbers of the gene will not be able tomate, resulting in speciation.D) Individuals with the mutation are not able to produce offspring and will be removed from the gene pool. The base of the right prism is a hexagon composed of a rectangle and two triangles. Find the volume of the righthexagonal prism using the formula V = Bh.3 inin anyone have the answer ?? 1. How does Dischord end up helping Milo on his quest? 2. How do Milos solutions for getting the princesses out of the Castle-in-the-Air show his growth since the beginning of the play? 3. In your own words, restate Rhyme and Reasons advice to Milo at the end of Act II. Express each decimal to fraction 106.28 Whom does Chavez blame for the problems facedby minorities?the US governmentthe minorities' countries of originThe powers that be make themselves richerby exploiting the poor. Our nation continuesto allow children to go hungry, and will noteven house its own people. The time is nowfor people, of all races and backgrounds, tosound the trumpets of change. As Dr. Kingproclaimed "There comes a time when peopleget tired of being trampled over by the ironfeet of oppression."other workersDONECesar ChavezUnited Farm Workers Union The height of a triangle is 2 less than 5 times its base. If the base of the triangle is x feet, and the area of the triangle is 12 square feet, whichequation models this situation?A. 5x^2-2x-24=0B. 5x^2-2x-12=0C. 5x^2-2x-6=0D. 25x^2-10x-24 = 0