Question

A ball of mass 100 g is moving with a velocity of 40 $m{s}^{-1}$. When a constant force is applied to it, it's velocity reaches 70 $m{s}^{-1}$.

Then which of the following is correct.

• A. Initial momentum = 7 $kgm{s}^{-1}$
• B. Final momentum = 4 $kgm{s}^{-1}$
• C. Initial momentum = 4 $kgm{s}^{-1}$
• D. Final Momentum = 7 $kgm{s}^{-1}$

Answer 1

Answer: (C), (D)

The correct options are
C

Initial momentum = 4 $kgm{s}^{-1}$

D

Final Momentum = 7 $kgm{s}^{-1}$

Given, Initial velocity(u) = 40 $m{s}^{-1}$ , Final velocity(v) = 70 $m{s}^{-1}$ , Mass = 100 g = 0.1 kg.

Initial Momentum = $mass\times initialvelocity$

=$0.1\times 40$

=$4kgm{s}^{-1}$.

Final Momentum = $mass\times finalvelocity$

=$0.1\times 70$

=$7kgm{s}^{-1}$.