Laws Of Motion Question 271
Question: 10,000 small balls, each weighing 1 gm, strike one square cm of area per second with a velocity 100 m/s in a normal direction and rebound with the same velocity. The value of pressure on the surface will be [MP PMT 1994]
Options:
A) $ 2\times 10^{3}N/m^{2} $
B) $ 2\times 10^{5}N/m^{2} $
C) $ 10^{7}N/m^{2} $
D) $ 2\times 10^{7}N/m^{2} $
Show Answer
Answer:
Correct Answer: D
Solution:
$ P=\frac{F}{A}=\frac{n[mv-(-mv)]}{A}=\frac{2mnv}{A} $
$ =\frac{2\times {{10}^{-3}}\times 10^{4}\times 10^{2}}{{{10}^{-4}}} $
$ =2\times 10^{7}N/m^{2} $
