Is a measurement is precuse it must also be accurate
Two trains are moving at 50 m/s in opposite directions on the same track. The engineers see simultaneously that they are on a collision course and apply the brakes when they are 1,100 m apart. Assuming both trains have the same acceleration, what must this acceleration be (in m/s2) if the trains are to stop just short of colliding
Answer:
Acceleration is 2.5 m/s^2
Explanation:
Let train 1 travel x meters and train 2 travels 1000-x meters
As per the las of acceleration
[tex]v^2 = u^2 + 2ax[/tex]
Substituting the given values, we get -
[tex]0 = 50^2 + 2ax\\ax = -1250\\[/tex]---Eq (1)
Similarly
[tex]0 = 50^2 + 2a(1000-x)\\a(1000-x) = 1250[/tex]-- Eq (2)
Substituting the value of ax from eq (1) into Eq(2), we get -
1000*a - 1250 = 1250
a = 2500/1000 = 2.5 m/s^2
PLEASE HELPPPPPP ME PLS PLS
which of the following is not a good working habit in doing an embroidery
Answer:
Where is following ??
Post proper Ques
A ball is dropped out of a window and hits the ground at 14.5 m/s. How long did it take to fall to the ground?
Answer:
Explanation:
Use the one-dimensional equation:
[tex]v_f=v_0+at[/tex] which says that the final velocity of a falling object is equal to its initial velocity times the acceleration of gravity times the time it takes to fall. We have the final velocity, -14.5 (negative because its direction is down and down is negative), initial velocity is 0 (because it was held still by someone before it was dropped), and acceleration is -9.8 (negative again, because direction is down while acceleration increases). Filling in:
-14.5 = 0 - 9.8t and
-14.5 = -9.8t so
t = 1.5 seconds
A drunken sailor stumbles 550 meters north, 500 meters northeast, then 450 meters northwest. What is the total displacement and the angle of the displacement
Answer:
Resultant displacement = 1222.3 m
Angle is 88.3 degree from +X axis.
Explanation:
A = 550 m north
B = 500 m north east
C = 450 m north west
Write in the vector form
A = 550 j
B = 500 (cos 45 i + sin 45 j ) = 353.6 i + 353.6 j
C = 450 ( - cos 45 i + sin 45 j ) = - 318.2 i + 318.2 j
Net displacement is given by
R = (353.6 - 318.2) i + (550 + 353.6 + 318.2) j
R = 35.4 i + 1221.8 j
The magnitude is
[tex]R = \sqrt{35.4^{2}+1221.8^{2}}R = 1222.3 m[/tex]
The direction is given by
[tex]tan\theta =\frac{1221.8}{35.4}\\\\\theta = 88.3^{o}[/tex]
what is the meaning of friend ?
Answer:
person that you know and like (not a member of your family), and who likes you
A student removes a 10.5 kg stereo amplifier from a shelf that is 1.82 m high. The amplifier is lowered at a constant speed to a height of 0.75 m. What is the work done by (a) the person and (b) the gravitational force that acts on the amplifier
Answer:
(a) the work done by the student is 110.1 J
(b) The gravitational force that acts on the amplifier is 102.9 N
Explanation:
Given;
mass of the amplifier, m = 10.5 kg
initial position of the amplifier, x₀ = 1.82 m
final position of the amplifier, x₁ =0.75 m
The dispalcement of the amplifier Δx = x₁ - x₀ = 1.82 m - 0.75 m = 1.07 m
(b) The gravitational force that acts on the amplifier;
F = mg
F = 10.5 x 9.8
F = 102.9 N
(a) the work done by the student is calculated as;
W = FΔx
W = 102.9 x 1.07
W = 110.1 J
a. Green light shines through a 100mm-diameter hole and is observed on a screen. If the hole diameter is increased by 20%, does the circular spot of light on the screen decrease in diameter, increase in diameter, or stay the same? Explain.
b. Green light shines through a 100-μ m-diameter hole and is observed on a screen. If the hole diameter is increased by 20%, does the circular spot of light on the screen decrease in diameter, increase in diameter, or stay the same? Explain.
Answer:
a) size of the bright spot is proportional to the hollow size
b) as the size of the hole increases, the circular point decreases.
Explanation:
a) In this case the diameter of the hole is much greater than the wavelength, as the size of the hole is many orders greater than the wavelength we are in the part of geometric optics,
Consequently the size of the bright spot is proportional to the hollow size.
Consequently the size increases
b) in this case the hole diameter d = 100 10⁻⁶m and the wavelength that for the green color is lam = 500 nm = 5 10⁻⁷ m
We see that angles are very small so the wavelength of the office is greater than the wavelength, but you can observe the effects of diffraction
d sin θ = 1.22 m λ
the numerical constant appears by solving the equation in polar coorθdinates, because the hole is circular
the first zero occurs for m = 1
sin θ = 1.22 λ / d
In these experiments the angles are small
sin θ = θ
we substitute
θ = 1.22 λ/ d
θ = 1.22 500 10⁻⁹ / 100 10⁻⁶
θ = 6.1 10⁻³
without the hole diameter increases by 20%
d’ = 1.2 d
we substitute
θ'= 1.22 λ / d'
θ’ = 1.22 λ /1.2 d
θ‘= 1.22 λ /d [tex]\frac{1}{1.22}[/tex]
θ ’= θ 0.83
θ ’= 6.1 10⁻³ 0.83
θ' = 5 10⁻³ rad
Therefore, the answer is that as the size of the hole increases, the circular point decreases.
The index of refraction of n-propyl alcohol is 1.39. Find the angle of refraction of light in that medium if light comes from air with an angle of incidence of 55 degrees.
Answer:
36.11 degrees
Explanation:
index of refraction n = sin i/sinr
i is the angle of incidence
r is the angle of refraction
Substitute into the expression
1.39 = sin55/sin(r)
1.39 = 0.8191/sin(r)
sin(r) = 0.8191/1.39
sin(r) = 0.5893
r = arcsin(0.5893)
r = 36.11
hence the angle of refraction of light is 36.11 degrees
To find the specific heat capacity of a solid of mass 600 g whose temperature was 40oC, it was placed in a calorimeter that contains 25 g of water 10oC. The mixture reached a final temperature of 25oC. How much is the metal's specific heat capacity? (Cwater = 4180 J/Kg.K)
500J/Kg.K
250J/Kg.K
174J/Kg.K
2000J/Kg.k
Answer and I will give you brainiliest
Answer:
m of solid = 600g = 0.6kg
T=40°C
It was placed in a calorimeter that contains 25g(0.025kg) of water at 10°C
Now. We would have considered the calorimeter in this solving because it will be at the same temp as the water which it is holding. Example... If you put a hot water inside a Cup... The cup itself will become hot and have the same temp as the water you put in it ...
But in this question... We'll Ignore the Calorimeter and the heat gained by it since no parameter was given for it and also We don't know the material which the calorimeter is made of.
So
Since the Solid is at a higher temp(40°)... It will lose heat to water; which is at a lower temp.
From the question... THE EQUILIBRIUM TEMPERATURE REACHED IS 25°C
Then
Temp Change for solid(heat loss) = 40-25=15°C
Temp Change for water(heat gain)= 25-10 =15°C
Heat lost by solid = Heat gained by water
MC∆T = MC∆T
0.6 x C x 15 = 0.025 x 4180 x 15
C= 0.025x4180x15÷(0.6x15)
C= 174.16 ~ 174J/Kg.K.
OPTION C IS LEGIT
How long would it take a 4,560 watt motor to raise a 166 kg piano to an apartment window
15 meters above the ground?
Answer:
Explanation:
We need the power equation here:
P = W/t where W is work and is defined as
W = F*displacement.
Force is a measure in Newtons, which is also weight. We have the mass of the piano, but we need to find the weight:
w = mg so
w = 166(9.8) so
w = 1600N, rounded to the correct number of sig dig. We use that now in the power equation:
[tex]4560=\frac{(1600)(15)}{t}[/tex] and isolating the unknown:
[tex]t=\frac{(1600)(15)}{4560}[/tex] so
t = 5.3 seconds
what happened in my room
Answer:
A GHOST CAME! Booooo!!!!!!Hah lol
PLEASE HELP! Daniel is 50.0 meters away from a building. He observes that his line-of-sight to the tip of the building makes an angle of 63.0° with the
horizontal. What is the height of the building?
A. 174 m
B. 110 m
C. 98 m
D. 50 m
Answer:
The height of building should be 98.13 m plus the height of Daniel. Since the 63° was measured from his eye level.
Explanation:
The diagram shows a transistor used in a circuit.
A signal with a small change in voltage is input into a circuit that includes a transistor connected to 4 resistors and 2 capacitors. The signal output from the transistor has a much larger change in voltage than the input.
What does the diagram show?
an NPN transistor used as an amplifier
an NPN transistor used as a switch
a PNP transistor used as an amplifier
a PNP transistor used as a switch
Answer:
a PNP transistor used as an amplifier
Explanation:
The diagram show a PNP transistor used as an amplifier.PNP transisitor having one 2 P type and the 1 N type of semiconductor.
What is PNP transistor?This bipolar PNP junction transistor is made up of three layers of semiconductor material, two of which are P-type & one of which is N-type. It consists of three terminals.
The transistor's emitter allows it to supply the majority of charge carriers. In relation to the ground, the emitter always is forward biased.
As a result, the base receives the vast majority of charge carriers. A transistor's emitter is strong and of modest size.
The collector collects the vast majority of the charge carrier delivered by the emitter. Reverse bias is always present at the collector-base junction.
The charge collector region is moderately mixed and capable of collecting the charge.
The diagram shows a transistor used in a circuit.
A signal with a small change in voltage is input into a circuit that includes a transistor connected to 4 resistors and 2 capacitors. The signal output from the transistor has a much larger change in voltage than the input.
The diagram show a PNP transistor used as an amplifier.
Hence option C is correct.
To learn more about the PNP transistors refer to the link;
https://brainly.com/question/1492057
please someone help me full out the blanks
4) The SI unit of time is second. why?
Answer:
Second, fundamental unit of time, now defined in terms of the radiation frequency at which atoms of the element cesium change from one state to another. The second was formerly defined as 1/86,400 of the mean solar day—i.e., the average period of rotation of the Earth on its axis relative to the Sun.
source britannica
Explanation:
A 3.0-A current is maintained in a simple circuit that consists of a resistor between the terminals of an ideal battery. If the battery supplies energy at a rate of 25 W, how large is the resistance
Answer:
[tex]R=2.78\ \Omega[/tex]
Explanation:
Given that,
The current flowing in the circuit, I = 3 A
The power of the battery, P = 25 W
We need to find the resistance of the battery. We know that the power of the battery is given by the formula as follows :
[tex]P=I^2R[/tex]
Put all the values to find R.
[tex]R=\dfrac{P}{I^2}\\\\R=\dfrac{25}{(3)^2}\\\\R=2.78\ \Omega[/tex]
So, the resistance is equal to [tex]2.78\ \Omega[/tex].
A. What is the change in internal energy for each of the following situations? q = 7.9 J out of the system and w = 3.6 J done on the system q = 1.5 J into the system and w = 7.5 J done on the system
Answer: [tex]-4.3\ J,\ 9\ J[/tex]
Explanation:
Given
(a)
Heat transfer [tex]Q=-7.9\ J\quad \text{taken}[/tex]
Work done [tex]W=-3.6\ J\quad \text{on the system}[/tex]
Change in the internal kinetic energy is
[tex]\Delta U=Q-W\\\Rightarrow \Delta U=-7.9-(-3.6)\\\Rightarrow \Delta U=-4.3\ J[/tex]
(b)
Heat transfer [tex]Q=1.5\ J\quad \text{given}[/tex]
Work done [tex]W=-7.5\ J\quad \text{on the system}[/tex]
Change in the internal kinetic energy is
[tex]\Delta U=Q-W\\\Rightarrow \Delta U=1.5-(-7.5)\\\Rightarrow \Delta U=9\ J[/tex]
3. How do you think a hot air balloon works?
Answer:hot air
Explanation:Hot air goes up, so when you put it in a hot air balloon fire is placed at the oppening to creat hot air and lift the balloon! :)
magnetism/ magnetic field ana magnetic forces
Answer:
Magnetism is a physical phenomenon that manifests itself in a force acting between magnets or other magnetized or magnetisable objects, and a force acting on moving electric charges, such as in current-carrying cables. The force action takes place by means of a magnetic field, which is generated by the objects themselves or otherwise. There are natural and artificial magnets. All magnets have two poles called the north pole and the south pole. The north pole of one magnet repels the north pole of another magnet and attracts the south pole of another magnet; the same with south poles.
Fill in the blanks. Power station produce electricity at __________.
Answer:
heat
Explanation:
heat is the answer hdhhdhdhdhdhdhdhdhdhd
A current is maintained in a simple circuit that consists of a resistor between the terminals of an ideal battery. If the battery supplies energy at a rate of W, how large is the resistance
Answer:
Resistance is as large as 2.8 ohm
Explanation:
Complete question
A 3.0 A current is maintained in a simple circuit that consists of a resistor between the terminals of an ideal battery. If the battery supplies energy at a rate of 25 W, how large is the resistance?
Solution -
The relation between Power and current is as follows
P = I^2*R
R = P/I^2
Were P = Power
R = resistance and
I = current
Given-
P = 25 W
I = 3.0 A
Substituting the given values, in above equation, we get -
R = 25/3.0^2
R = 2.8 ohm
Give an example of a vertical motion with a positive velocity and a negative acceleration. Give an example of a vertical motion with a negative velocity and a negative acceleration.
Answer:
An example of positive velocity is throwing a ball upwards
An example of downward vertical velocity is when an object is dropped, for example a ball dropped from a height
Explanation:
In a vertical movement the acceleration is always downwards, therefore negative since it is created by the attraction of the Earth on the body.
An example of positive velocity is throwing a ball upwards
An example of downward vertical velocity is when an object is dropped, for example a ball dropped from a height
allung d Uall, Wily
In which condition is mirage seen ? Why is light dispersed ?
Answer:
Mirage is a phenomenon which can be seen when the surface air gets heated up and it becomes lighter. Lighter air moves up in the atmoshphere.
Explanation:
When the lighter air from cooler areas to warmer areas are refracted and they bent upwards.and it dispers
,
Physics part 1
I need help answering these
Answer:
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Many adventures like to go rafting on the Colorado River through Grand Canyon National Park. There are many locations where the river becomes more narrow, both the distance between the canyon walls as well as the depth changes due to debris like boulders on the bottom of the river; this leads to changes in the water speed. In the park, the Colorado River has an average width of 100m and an average depth of 8m, and an average speed of 3 m/s. At the Lava Falls Rapids, the river has an average width of about 25m and an average depth of about 15m. What is the approximate speed of the water in this location
Answer:
6.4 m/s
Explanation:
Given that :
The average width of the Colorado river = 100 m
Average depth of the river is = 8 m
Therefore, area = [tex]$A_1= 100 \ m \times 8 \ m$[/tex]
Speed of the river, [tex]$v_1 = 3 \ m/s$[/tex]
After the lava falls on the river,
Width of the river becomes = 25 m
Depth of the river became = 15 m
Therefore, area = [tex]$A_2= 25 \ m \times 15 \ m$[/tex]
Now, since the volume flow rate of the Colorado river is same, then from the Continuity equation,
[tex]$Q_1=Q_2$[/tex]
[tex]$A_1v_1=A_2v_2$[/tex]
∴ [tex]$100 \times 8 \times3 = 25 \times 15 \times v_2$[/tex]
[tex]$v_2=\frac{100 \times 8 \times 3}{25 \times 15}$[/tex]
= 6.4 m/s
Therefore, the speed of the river in this location is 6.4 m/s
C.
A palm fruit dropped to the ground from the top of
a tree 45m tall. How long does it take to reach the
ground? A. 9s B. 4.5s C. 6 D. 7.5s E. 35
(g = 10ms2).
Answer:
b 4.5
Explanation:
time=distance/speed
Convert 15000kg/m cube
into gm/cm cube
please write the process also
Answer:
15000 Kilograms/Cubic Meters (kg/m3) = 15 Grams/Cubic Centimeters (g/cm3)
Explanation:
1 g/cm3 is equal to 1000 kilogram/cubic meter. To convert 100 gram into kg then divide it by 1000 i.e. 100/1000 = 0.1 kg. To convert any value of gm/cm3 into kg/m3 then multiply it by 1000.
15000 kg / m^3 =
15000 × 10^3 g / m^3 =
15000 × 10^3 × 10^3 mg / m^3 =
15 × 10^9 mg / m^3 =
15 × 10^9 × 10^(-3) mg / dm^3 =
15 × 10^9 × 10^(-3) × 10^(-3) mg / cm^3 =
15 × 10^9 × 10^(-6) mg / cm^3 =
15 × 10^( 9 - 6 ) mg / cm^3 =
15 × 10^3 mg / cm^3 =
15000 mg / cm^3 =
Look : We found the exact thing we had ...
WoW ...
We got a point ;
Remember from now on :
kg / m^3 = mg / cm^3
Seawater fills a tank to a depth of 12 ft. If the specific gravity of seawater is 1.03 and the atmospheric pressure at this location is 14.8 psi, the absolute pressure (psi) at the bottom of the tank is most nearly:______.
A. 5.4
B. 20.2
C. 26.8
D. 27.2
E. 10.8
Answer: (b)
Explanation:
Given
Depth of tank is [tex]h=12\ ft\ \text{or}\ 3.65\ m[/tex]
Specific gravity of seawater is [tex]S.G.=1.03[/tex]
Pressure difference due to column of water is
[tex]\Rightarrow \Delta P=\rho gh\\\Rightarrow \Delta P=1.03\times 10^3\times 9.8\times 3.65\\\Rightarrow \Delta P=36.84\times 10^3\ Pa\ \text{or}\\\Rightarrow \Delta P=5.34\ psi[/tex]
So, absolute pressure is given by
[tex]\Rightarrow P_{abs}=P_{atm}+\Delta P\\\Rightarrow P_{abs}=14.8+5.34\\\Rightarrow P_{abs}=20.14\approx 20.2\ psi[/tex]
Thus, option (b) is correct.