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victus00 [196]
3 years ago
6

A train travel on a straight track passing signal A at 20ms-1. It accelerates uniformly a 3ms-2 and reaches signal B 120m furthe

than A. At B, the velocity of the train is? ​
Physics
1 answer:
IgorLugansk [536]3 years ago
3 0

Since acceleration is uniform, if the velocity at point B is <em>v</em>, then

v^2 - \left(20\dfrac{\rm m}{\rm s}\right)^2 = 2\left(3\dfrac{\rm m}{\mathrm s^2}\right)(120\,\mathrm m)

Solve for <em>v</em> :

v^2 = \left(20\dfrac{\rm m}{\rm s}\right)^2 + 2\left(3\dfrac{\rm m}{\mathrm s^2}\right)(120\,\mathrm m) \\\\ v = \sqrt{\left(20\dfrac{\rm m}{\rm s}\right)^2 + 2\left(3\dfrac{\rm m}{\mathrm s^2}\right)(120\,\mathrm m)} \\\\ \boxed{v \approx 34 \dfrac{\rm m}{\rm s}}

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Explanation:

The nearest star to the Earth is the red dwarf star Proxima Centauri, at a distance of 4.218 light-years.  

Light year is the unit of distance covered by the heavenly bodies. 1 light year is equal to :

1\ light\ year=3.72\times 10^{17}\ inches

So, 4.218\ light\ year=4.218\times 3.72\times 10^{17}\ inches

4.218\ light\ year=1.56\times 10^{18}\ inches

We need to convert 4.218 light-years barley corns.  

Since, 1 barleycorn = 1/3 inch  

1\ inch=3\ barleycorn

1.56\times 10^{18}\ inches=3\times 1.56\times 10^{18}=4.68\times 10^{18}\ barleycorn

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3 years ago
A student wants to determine the effect of mass on kinetic energy. She will drop two balls of the same size into a pool of water
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She should drop two balls with different masses from the same height

Explanation:

4 0
2 years ago
a. As you coast down a hill on your bicycle, you accelerate at 0.5 m/s2. If the total mass of your body and the bicycle is 80 ki
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Cheetah mothers perform a number of different behaviors. They and their cubs stay in one place for only four days, moving on bef
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Answer:

Cheetah cubs are in danger from predators like lions and hyenas which can track their prey by scent and so the mother and her cubs leave an area when their scent is too strong so that they are not hunted and the cubs survive.

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3 years ago
How do i figure out this question?
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Answer:

0.75 g/cm^3

Explanation:

The formula for density:

\rho = \frac{m}{V}

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8 0
3 years ago
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