Q.

A spherical body of mass 100 g is dropped from a height of 10 m from the ground. After hitting the ground, the body rebounds to a height of 5 m. The impulse of force imparted by the ground to the body is given by (given g=9.8 m/s2)           [2024]

1 4.32 kg ms-1  
2 43.2 kg ms-1  
3 23.9 kg ms-1  
4 2.39 kg ms-1  

Ans.

(4)

m=100g=0.1 kg, h1=10 m, h2=5 m

u=2gh1=2×98 m/s

v=2gh2=98 m/s

Impulse =ΔP=Pf-Pi

=0.1[98+2×98]

2.39 kg m/s