A ball of mass 50 g is dropped from a height h = 10 m . It rebounds losing 75 per cent of its kinetic energy . If it remain in contact with the ground for `Deltat = 0.01` s , the impulse of the impact force is

Options

A. 1.3 N-s
B. 1.06 N-s
C. 1300 N-s
D. 1.05

Answer

B

Explanation

`v_(1)=sqrt(2gh)=sqrt(2xx10xx10)=10sqrt(2)`
`k_(2)=1/4k_(1)rArr v_(2)^(2)=1/4v_(1)^(2)`
`:. v_(2)=(v_(1))/2=5sqrt(2)`
`|DeltaP|=|-mv_(2)-(mv_(1))|=m|-v_(2)-v_(1)|`
`|DeltaP|=50xx10^(-3)xx3/2xx10sqrt(2)=(15xx10^(-1))/(sqrt(2))`
`J=DeltaP=1.05 N-s`