Question

A force of 10N changes the velocity of a body from 5 m/s to 10 m/s in 10 sec. The force required to bring about the same change in 5 seconds is

Answer 1

Answer:

Force is defined as the rate of change in momentum. The change in momentum in both the cases is the same. Only the rate differs as the time taken is different.

Let dP be the change in momentum.

In the first case, the change happened in 5 second. And the force required was 10N.

So, dP/5 = 10

=> dP = 10 * 5 = 50

Now we need to calculate the force required to have to same change in momentum in 3 seconds.

So the required force is dP/3 = 50/3 N or 16.67 N

(The initial and final velocities are irrelevant in this question).......