Starting from rest at the top of an inclined plane a body reaches the

1.	Starting from rest at the top of an inclined plane a body reaches the bottom of the inclined plane in 4 seconds. At what time does the body cover one-fourth the distance starting from rest at the top?A. 1 second B. 2 second C. 3 second D. 4 second
Answer» Let “s” be the total distance and “a” be the acceleration. Now, we know that initially the body is at rest. Now, from the equations of motion, we get, \(s=ut+\frac{1}{2}at^2\)…………1 \(s = \frac{1}{2}a\times4^2\)…………2 To find the time taken for covering \(\frac{s}{4}\) , we put = \(\frac{s}{4}\) in equation 1 above. So, \(\frac{s}{4} =\frac{1}{2}\,a\times\,t^2\) ….…….3 Now, dividing equation 2 by 3, we get, t = 2 s Hence, option B is correct.

Starting from rest at the top of an inclined plane a body reaches the bottom of the inclined plane in 4 seconds. At what time does the body cover one-fourth the distance starting from rest at the top?A. 1 second B. 2 second C. 3 second D. 4 second

Answer»

Let “s” be the total distance and “a” be the acceleration.

Now, we know that initially the body is at rest.

Now, from the equations of motion, we get,

\(s=ut+\frac{1}{2}at^2\)…………1

\(s = \frac{1}{2}a\times4^2\)…………2

To find the time taken for covering \(\frac{s}{4}\) , we put = \(\frac{s}{4}\) in equation 1 above.

So, \(\frac{s}{4} =\frac{1}{2}\,a\times\,t^2\) ….…….3

Now, dividing equation 2 by 3,

we get, t = 2 s

Hence, option B is correct.