Question

A body of mass $5\, kg$ is acted on by a force $F$ which varies with time $t$ as shown in the given figure. Then the momentum gained by the body at the end of $10$ seconds is

• A. $0\, kg\, m\, s ^{-1}$
• B. $100\, kg\, m\, s ^{-1}$
• C. $140\, kg\, m\, s ^{-1}$
• D. $200\, kg\, m\, s ^{-1}$

Answer 1

Answer: (C)

Change in momentum = Area under $F-t$ graph
= area of trapezium $O A B C $
$= \frac{1}{2}(10+4) \times 20=140 \,kg\, m\, s ^{-1}$