A body of mass 2 kg collides with a wall with speed 100 m / s and rebounds with same speed. If the time of contact was 1/50 second, the force exerted on the wall is

Options

A. 8 N
B. ` 2 xx 10 ^( 4 ) ` N
C. 4 N
D. ` 10 ^ ( 4 ) ` N

Answer

B

Explanation

We know that, ` F = ( dp ) /( dt ) = ( mdv ) /( dt ) = ( m xx 2v ) /( 1 // 50 ) `
= ` ( 2xx 2xx 100 ) /( 1 //50 ) = 2xx 10 ^4 ` N