Question

10,000 small balls, each weighing 1 g strike one square cm of area per second with a velocity

100 ms–1 in a normal direction and rebound with the same velocity. The value of pressure on the surface

will be

(a) 2*10(3)
(b) 2*10(5)
(c) 10(7)
(d) 2*10(7)​

Answer 1

$\boxed{\bold{Pressure = \dfrac{Force}{Area}}}\\\\\\F=ma\\\\F=m.\dfrac{\Delta v}{\Delta t}\\\\\\\text{mass of each ball}=1g=10^{-3}\:kg\\\\\text{initial velocity=-100\:m/s}\\\\\text{rebound velocity=100\:m/s}\\\\\text{Change in velocity,}\Delta v=100-(-100)=200\:m/s\\\\\text{Change in time,}\Delta t= 1s\\\\\text{Force exerted by one ball, F}=10^{-3}\:kg\times200=2\times10^{-1}N\\\\\\\text{Total Force exerted}= nF=10,000\times(2\times10^{-1})=2\times10^3N\\\\\text{Area} = 1 cm^2 = 10^{-4}\:m^2\\\\\text{Pressure}=\dfrac{2\times10^{3}}{10^{-4}}=2\times10^7\:Pa$

Answer 2

Answer:

2×10^7 N/m^2

opt4)

hope it helps u

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