NEET Solved Paper 2014 Question 5

Question: The force F acting on a particle of mass m is indicated by the force-time graph shown below. The change in momentum of the particle over the time interval from zero to 8 s is [AIPMT 2014]

Options:

A) 24 Ns

B) 20 Ns

C) 12Ns

D) 6Ns

Show Answer

Answer:

Correct Answer: C

Solution:

The area under F-t graph gives change in momentum.

For 0 to $ 2,s,\Delta p _1=\frac{1}{2}\times 2\times 6=6kg-m/s $ For 2 to 4 s,

$ \Delta p _2=2\times (-3)=-6,kg-m/s $ For 4 to 8s, $ \Delta P _3=(4)\times 3=+12kg-m/s $

So, total change in momentum for 0 to 8 s $ \Delta p _{net}=\Delta p _1+\Delta p _2+\Delta p _3=(+6-6+12) $ $ =12kg-m/s=12Ns $