Answer to Question #285097 in Mechanics | Relativity for Amnisha

Question

A train started from rest and moved with constant acceleration. At one time it was travelling at 33 m/s and 160m farther on it was travelling 54m /s

Calculate (a) acceleration (b) time required to travel 160m(c)distance moved from rest to time the train had a speed of 33m/s

Answer 1

Explanations & Calculations

• Since the acceleration is uniform, you can use any of the 4 motion equations appropriately.
• Thing to take into consideration is that the initial velocity is zero.

a).

• For this you can use the formula $\small v^2 = u^2+2as$ from the starting point to the point 160m away, as you are given the values of all variable except $a$ which is the acceleration you need to find.
• Use the units correctly and get the answer.

b).

• For this you can use $s=ut+\frac{1}{2}at^2$ from the start to the point 160m away. You have now found the value of acceleration and that could be used here to calculate the time.

c).

• For this you can use $v^2 = u^2+2as$ from start to the point where the train had 33 m/s speed as you now know the values of all the variables except $s$ which is the displacement that you need to calculate.

• You now can probably give it a try.