Q. While waiting in a car at a stoplight, and 80 kg man and his car are suddenly accelerated to a speed of $5\ ms^{- 1}$ as a result or rear end colllison. If the time of impact is 0.4 s, find the average force on the man
A) 100 N
B) 200 N
C) 500 N
D) 1000 N
Explanation
(d) Impulse = Change in momentum
$F \times t = m(v - u)$
$F \times 0.4 = 80(5 - 0) \Rightarrow F = \frac{80 \times 5}{0.4} = 1000$N
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.