Laws Of Motion Question 262
Question: A ball of mass 0.5 kg moving with a velocity of 2 m/sec strikes a wall normally and bounces back with the same speed. If the time of contact between the ball and the wall is one millisecond, the average force exerted by the wall on the ball is[CBSE PMT 1990]
Options:
A) 2000 N
B) 1000 N
C) 5000 N
D) 125 N
Show Answer
Answer:
Correct Answer: A
Solution:
$ F _{av}=\frac{\Delta p}{\Delta t}=\frac{mv-(-mv)}{\Delta t}=\frac{2mv}{\Delta t}=\frac{2\times 0.5\times 2}{{{10}^{-3}}} $ = 2000 N
