Answer:
B
Explanation:
the external force was applied
bold completed over 100m in 9.58
seconds what is his average speed
Answer:
At the Berlin 2009 World Championships, Bolt set a world record time of 9.58 seconds for the 100m race, notching a top speed of 27.8 miles per hour (44.72 kilometers per hour) between meters 60 and 80, with an average speed of 23.5 mph.
Explanation:
A 2.0-kg block starts from rest on the positive x axis 3.0 m from the origin and thereafter has an acceleration given by in m/s2. At the end of 2.0 s its angular momentum about the origin is:
Answer:
hello your question is incomplete below is the complete question
A 2.0 kg block starts from rest on a positive x axis 3.0m from the origin and thereafter has an acceleration given by a= 4.0i - 3.0jin m/s2. At the end of 2.0 s, its angular momentum about the origin is ______.
answer : L = ( 2 kg ) [(-18m^2/s)k]
Explanation:
velocity vector(v) = (4.0i - 3.0j )(2.0s)
position vector(r) = ( 3.0m)i
determine the angular momentum about the origin
L = m ( r * v )
attached below is the detailed solution
Answer:
Angular momentum about the origin = [tex](-36kg.rad/s)k[/tex]Explanation:
Given the acceleration,
[tex]v(t) = 4ti - 3tj[/tex]
So,
[tex]v(2) = 8i - 6j[/tex]
similarly,
[tex]x(t) = (3 + 2t^2) i - 1.5t^2 j[/tex]
so,
[tex]x(2) = 11i - 6j[/tex]
Angular momentum,
[tex]=mx(2)*v(2)\\\\=2*((-6x0-0x-6)i +(0x8-11x0)j +(11x-6--6x8)k)\\\\=2*(0i +0j -18k)\\\\=(-36kg.rad/s)k[/tex]
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Exercise 25
1. Ablock of wood is 10 cm long, by 4 cm broad
by 15 cm thick. The block weighs 31 g.
Find the density of the wood in kg/m!
Explanation:
d=m/v. volume in cm^3 is 10x4x15=600cm^3. 31g/600cm^3 converts to .031kg/.0006m^3.
A block is released from rest at the top of a hill of height h. If there is negligible friction between the block and the hill, the block arrives at the bottom of the hill with speed v.
Answer:
v / √2
Explanation:
A blocked from rest at the top of a hill of height h it there is negligible friction between the block and the hill, the block arrives at the bottom of the hill with speed. The block is released from rest at the top of another hill with a rough surface and height h. if one-half of the initial mechanical energy of the block Earth System is lost due to friction as the block descends the hill, the block will reach the bottom of the hill with a speed of?
Solution:
For the first block block, its potential energy at the top of the hill when it is at rest is converted to kinetic energy after release with a velocity v.
The kinetic energy = (1/2)mv², where m is the mass of the block.
For the other block placed on the top of the rough hill, the mechanical energy (kinetic energy) is halved due to the roughness of the hill. If u is the speed of this block at the bottom of the hill then:
kinetic energy of block on the rough hill = (1//2)mu²
Hence:
(1//2)mu² = half of main system kinetic energy
(1//2)mu² = 1/2 * (1/2)mv²
mu² = (1/2)mv²
u² = (1/2)v²
u = √(v²/2)
u = v / √2
Hence the speed at the bottom of the rock of the block placed on the rough surface is v / √2
In the experiment shown below, which is greater, the force of gravity on the pith balls (Fg) or the electrostatic force between them (Fq)?
Fg > Fq
Fg = Fq
Fg < Fq
Not enough information is given.
Answer: Fg < Fq
Explanation: just took the lab test edge 2020
The electromagnetic force is greater than the gravitational force option third Fg < Fq is correct.
What is the electrostatic force?It is a force imposed by one charge on another as a result of the field. The electrostatic force produced by one line charge on another line charge separated by r is determined by the charge potency of each charge as well as the separation distance between them.
Force of gravity is given by:
[tex]\rm F_g=\dfrac{Gm_1m_2}{r^2}[/tex]
The electrostatic force is given by:
[tex]\rm F_q = \dfrac{kq_1q_2}{r^2}[/tex]
On the atomic scale, electrons, for example, have very little mass but a very large charge. As a result, electromagnetic forces rule.
Thus, the electromagnetic force is greater than the gravitational force option third Fg < Fq is correct.
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Near the surface of Earth, what is the acceleration of an object due to the force of gravity? !!!!! Please answer !!!!!
Answer:
Weight. Recall that the acceleration of a free-falling object near Earth's surface is approximately g=9.80m/s2 g = 9.80 m/s 2 . The force causing this acceleration is called the weight of the object, and from Newton's second law, it has the value mg.
Explanation:
The law of conservation of mass states that mass can never be created or destroyed, only changed. true or faulse
Answer:
true
Explanation:
The law of conservation of mass states that in a chemical reaction mass is neither created nor destroyed. For example, the carbon atom in coal becomes carbon dioxide when it is burned. The carbon atom changes from a solid structure to a gas but its mass does not change.
What energy transformations take place from the outlet charger to the ringing phone?
Explain how the Law of Conservation of Energy applies to the energy
transformations that occur from the outlet charger to the ringing phone.
Answer:
Chemical energy transformations take place from the outlet charger to the ringing phone.
Explanation:
chemical energy
While charging the mobile electrical energy gets transformed into chemical energy. Most of the contemporary mobile phone batteries are lithium-ion batteries where the power is saved by the chemical transformations in the ionic structure of the battery. When the power gets into the mobile phone it is transformed and collected as chemical energy inside of the battery and when we utilize the mobile the earlier saved chemical energy is again transformed into electrical energy.
The energy transformation that takes place from the outlet charger to the
ringing phone is electrical energy from the outlet is converted to chemical
energy and back to electrical energy and sound energy when the phone is
being used and ringing.
The charger provides a source of electrical energy which gets converted to
chemical energy stored in the battery. During use, the chemical energy gets
converted to electrical energy to power the phone and to sound energy
when it rings with heat energy being dissipated also.
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what happens when a temperature
increases.
Answer:
if the tempertaure is increase it effects us very badly. it affects not only us . it effects our whole enviroment.
3 Kyra and Pari are timing how long it takes for 1 g of sugar to dissolve in hot water.
Kyra records a time of 24.3 seconds. Pari records a time of 24 seconds. Whose reading
is more precise? Why?
Answer:
Kyra is more precise.
Explanation:
Kyra is more precise as she has included the exact point second it had dissolved whereas Pari just rounded it to the closest number making her write a whole number that was rounded down.
What is the average speed of a race car that moved 20 kilometers in 10 minutes?
Answer:21
Explanation:every body said
is vibrating considered work
Answer: no it shouldn't be
Explanation:
the specific heat of gold is 0.031 calories degrees Celsius and the specific heat of silver is 0.057 calories degrees Celsius so if equal. amounts of each metal are exposed to equal heating which will heat up faster
Answer:
Explanation:
Given:
Specific heat of gold = 0.031cal/°C
Specific heat of silver = 0.057cal/°C
To know the metals that will heat up faster, we must understand the meaning of specific heat capacity.
It is the amount of heat required to raise the temperature of 1g of a substance by 1°C.
Now,
The higher the specific heat capacity the more energy it is required to heat up the substance.
So, Gold with a specific heat capacity of 0.031cal/°C will heat up faster.
what polarity must the red tip of the compass needle be since it points toward the south pole of the magnet?
Answer: positive
Explanation: because opposites attract and north=positive and south=negative the answer should be positive.
The polarity of the red tip of the compass needle must be at the north of the earth, since it points toward the south pole of the magnet.
What is meant by polarity of a magnet ?Polarity of a magnet is defined as the orientation of both the north and south poles of the magnet in space.
Here,
We know that, the opposite poles attract.
The magnetic needle is arranged in a such a way that, the red tip of the magnetic compass needle is actually pointing towards the geographic north pole of the earth.
In order to point the compass needle towards the magnetic south pole, the south pole of the magnet must be located in the geographic north pole.
Hence,
The polarity of the red tip of the compass needle must be at the north of the earth, since it points toward the south pole of the magnet.
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define steam distillation
Answer:
Steam distillation is a separation process which consists in distilling water together with other volatile and non-volatile components.
Study the distance-time graph, showing the distances that eight different things cover in 120 seconds or less. The letters below correspond to the lines on the graph. For each object, calculate the average speed, and then match it with the closest correct answer.
A:
B:
C:
D:
E:
F:
G:
H:
Answer:
This question appear incomplete
Explanation:
This question appear incomplete because there is no list of closest correct answer there. Although can still be well attempted.
The formula to be used here is
average speed = distance ÷ time
The unit of speed here would be meters per second (m/s). However, some of the lines do not really fall on a measurable line on the graph and can only be "best assumed".
A: distance is 1600 meters
time appear to be 4 seconds (definitely less than 5 seconds according to the graph).
speed = 1600 ÷ 4
speed = 400 m/s
B: distance is 1600 meters
time appear to be 18 seconds (definitely less than 20 seconds according to the graph)
speed = 1600 ÷ 18
speed = 88.89 m/s
C: distance is 1600 meters
time is 65 seconds
speed = 1600 ÷ 65
speed = 24.62 m/s
D: distance is 1600 meters
time is 105 seconds
speed = 1600 ÷ 105
speed = 15.24 m/s
E: distance is 1100 meters
time is 120 seconds
speed = 1100 ÷ 120
speed = 9.17 m/s
F: distance is 500 meters
time is 120 seconds
speed = 500 ÷ 120
speed = 4.17 m/s
G: distance appear to be 250 meters
time is 120 seconds
speed = 250 ÷ 120
speed = 2.08 m/s
H: distance appear to be 50 meters
time is 120 seconds
speed = 50 ÷ 120
speed = 0.42 m/s
The average speed for each object are:
1. The average speed of A is 400 m/s
2. The average speed of B is 88.89 m/s
3. The average speed of C is 24.62 m/s
4. The average speed of D is 15.24 m/s
5. The average speed of E is 9.17 m/s
6. The average speed of F is 4.17 m/s
7. The average speed of G is 2.08 m/s
8. The average speed of H is 0.33 m/s
Average speed is defined as the total distance travelled divided by the total time taken to cover the distance.
Average speed = Total distance / total timeWith the above formula, we can obtain the average speed for each object as follow:
1. Determination of average speed of A
Total distance = 1600
Total time = 4 s
Average speed =?Average speed = 1600 / 4
Average speed of A = 400 m/s2. Determination of average speed of B
Total distance = 1600
Total time = 18 s
Average speed =?Average speed = 1600 / 18
Average speed of B = 88.89 m/s3. Determination of average speed of C
Total distance = 1600
Total time = 65 s
Average speed =?Average speed = 1600 / 65
Average speed of C = 24.62 m/s4. Determination of average speed of D
Total distance = 1600
Total time = 105 s
Average speed =?Average speed = 1600 / 105
Average speed of D = 15.24 m/s5. Determination of average speed of E
Total distance = 1100
Total time = 120 s
Average speed =?Average speed = 1100 / 120
Average speed of E = 9.17 m/s6. Determination of average speed of F
Total distance = 500
Total time = 120 s
Average speed =?Average speed = 500 / 120
Average speed of F = 4.17 m/s7. Determination of average speed of G
Total distance = 250
Total time = 120 s
Average speed =?Average speed = 250 / 120
Average speed of G = 2.08 m/s8. Determination of average speed of H
Total distance = 40
Total time = 120 s
Average speed =?Average speed = 40 / 120
Average speed of H = 0.33 m/sLearn more: https://brainly.com/question/14988345
A car of mass 1000 kg travelling at a velocity of 25 m/s collides with another car of mass 1500kg which is at rest. The two cars stick and move off together. What is the velocity of the two cars after the collision?
Answer:
The velocity of the two cars is 10 m/s after the collision.
Explanation:
Law Of Conservation Of Linear Momentum
The total momentum of a system of bodies is conserved unless an external force is applied to it. The formula for the momentum of a body with mass m and velocity v is
P=m.v
If we have a system of bodies, then the total momentum is the sum of them all
[tex]P=m_1v_1+m_2v_2+...+m_nv_n[/tex]
If some collision occurs, the velocities change to v' and the final momentum is:
[tex]P'=m_1v'_1+m_2v'_2+...+m_nv'_n[/tex]
In a system of two masses, the law of conservation of linear momentum takes the form:
[tex]m_1v_1+m_2v_2=m_1v'_1+m_2v'_2[/tex]
If both masses stick together after the collision at a common speed v', then:
[tex]m_1v_1+m_2v_2=(m_1+m_2)v'[/tex]
The car of mass m1=1000 Kg travels at v1=25 m/s and collides with another car of m2=1500 Kg which is at rest (v2=0).
Knowing both cars stick and move together after the collision, their velocity is found solving for v':
[tex]\displaystyle v'=\frac{m_1v_1+m_2v_2}{m_1+m_2}[/tex]
[tex]\displaystyle v'=\frac{1000*25+1500*0}{1000+1500}[/tex]
[tex]\displaystyle v'=\frac{25000}{2500}[/tex]
v' = 10 m/s
The velocity of the two cars is 10 m/s after the collision.
Please find attached photograph for your answer.
fill in the blanks
a. Work is assosiated with ___________ and _________ .
Answer: Job and career
Explanation:
Work is associated with job and career. If somebody is having a great career and if somebody wants a great career he will look for a job that is fitting his career and in that way, he will work for it to have an even better career which will bring him a better job.
A 0.17 kg ball of dough is thrown straight up into the air with an initial speed of 12 m/s. The acceleration of gravity is 9.81 m/s 2 . a) What is its momentum at its maximum height? Answer in units of kg · m/s
Answer:
The momentum of the ball at the maximum height is zero (0 kg.m/s).
Explanation:
Given;
mass of the ball, m = 0.17 kg
initial velocity of the ball, u = 12 m/s
acceleration due to gravity, g = 9.81 m/s²
At maximum height the final velocity of the ball, v = 0
Momentum of the ball at the maximum height is given as;
P = mv
P = (0.17)(0)
P = 0 kg.m/s
Therefore, the momentum of the ball at the maximum height is zero (0).
what is relative density?
How many meters are in 22,053 kilometers? If there are 1,000 meters in one kilometer
Answer:
50m
Explanation:
How is sea salt harvested from the ocean? Name and explain the process.
Answer:
Sea salt is harvested by evaporating the ocean water away and generally has little to zero processing involved. Major sea salt manufacturers pump sea water into huge shallow “ponds” and allow the sun to evaporate the water... Before harvesting seawater, be sure the body of water you are using is not polluted.
Explanation:
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The force of gravity is
_m/s2
The force of gravity is positive 9.8m/s^2.
Rodney hits a 0.060 kg tennis ball straight up with a speed of 15 m/s from a height of 2.2 m above the ground. How fast is the ball going when it is 9.5 m above the ground?
Answer:
Explanation:
From the question we are told that
The mass of the tennis ball is [tex]m = 0.060 \ kg[/tex]
The speed is [tex]u = 15 \ m/s[/tex]
The initial height of the ball is [tex]h_o = 2.2 \ m[/tex]
The height considered is [tex]h = 9.5 \ m[/tex]
Generally the time taken to reach the considered height is mathematically evaluated from the equation of motion as follows
[tex]h = h_o + ut - \frac{1}{2} gt^2[/tex]
=> [tex]9.5 = 2.2 + 15t - \frac{1}{2} * 9.8 t^2[/tex]
=> [tex]7.3 = 15t - 4.9t^2[/tex]
=> [tex]4.9t^2 -15t + 7.3[/tex]
solving the above equation using quadratic formula
[tex]t= 0.6070 \ s[/tex] and [tex]t_1 = 2.454 \ s[/tex]
Generally from kinematic equation we have that
[tex]v = u - gt[/tex]
=> [tex]v= 15 - 9.8 * 0.6070[/tex]
=> [tex]v= 9.0514 \ m/s[/tex]
Note if we had used the second values of time the velocity at 9.5 \ m would have been negative which is not correct given that at maximum height velocity is zero
A person with a mass of 75 kg is accelerated to 3m/s2 how much force applied to him
Answer:
225 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 75 × 3
We have the final answer as
225 NHope this helps you
Can someone explain what is force constant k in Hooke’s law
F = kx
Answer:
answer is in photo
what is the weight of a 15 kg object
to get weight multiply Mass by 9.8
weight =9.8x15=147N
4) Choose Yes or No next to the descriptions to indicate whether or not an object
is accelerating,
A car slows down,
A car stays the same speed,
A car goes faster,
Luke walks at a constant speed of 4 mph,
Luke walks north at a constant speed of 4 mph,
Luke walks north at a constant speed of 4 mph, turns right, and walks
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Which equation below is correctly balanced?
A 2Na + O2 ---> 2Na2O
B Sn + 2KOH ---> K2SnO2 + 2H2
C AsCl3 + 3H2O ---> 3HCl + As(OH)3
D H2 + O2 ---> H2O
Answer:
D H2 + O2 ---> H2O
Explanation:
Answer:
I am not sure what the answer is but keep reading.
Explanation:
The answer is not D or A for sure
Which type of energies make up the mechanical energy of a roller coaster moving along a track?
Answer:
gravitational potential energy and kinetic energy
Explanation: