Question

A constant retarding force of 100 N is applied to a body of mass 60 kg moving initially with a speed of 5 m/s. What is the change in momentum of the body when the body comes to a halt?

• A. 300 kg-m
• B. 300 kg-s
• C. 300 kg ms^-1
• D. None

Answer 1

The correct option is C

300 kg ms^-1

Step 1: Given data

Applied force $F=-100N$ [Since, the force is retarding]

Mass of the body $m=60kg$

Initial velocity $u=5m/s$

Final velocity $v=0m/s$

Step 2: Finding change in momentum

Change in momentum $\Delta p$ can be given as below:

$\Delta p=m(v-u)$

Substituting the values we have,

$\Delta p=60(0-5)$

$\Delta p=-300kgm{s}^{-1}$

Magnitude of change of momentum$=300kgm{s}^{-1}$

Thus, option (c) is correct.