Question

A body moves due north with velocity 40 m/s. A force is applied

on it and the body continues to move due north with velocity 35 m/s. W. .What is the direction of rate of change of momentum,if it takes

some time for that change and what is the direction of applied

external force?​

Answer 1

Answer:

the direction of rate of change of the momentum is against the motion of the body, that is, downward.

The applied force is also against the direction of motion of the body, downward.

Explanation:

The change in the momentum of a body, if the mass of the body is constant, is given by the following formula:

$\Delta p=\Delta (mv)\\\\\Delta p=m\Delta v$

p: momentum

m: mass

$\Delta v$:  change in the velocity

The sign of the change in the velocity determines the direction of rate of change. Then you have:

$\Delta v=v_2-v_1$

v2: final velocity = 35m/s

v1: initial velocity = 40m/s

$\Delta v =35m/s-40m/s=-5m/s$

Hence, the direction of rate of change of the momentum is against the motion of the body, that is, downward.

The applied force is also against the direction of motion of the body, downward.