Answer:
Explanation:
a ) Applying law of conservation mechanical energy
1/2 mv² = mgh
v =√ 2gh
= √ 2 x 9.8 x 3
= 7.67 m /s
b ) Applying law of conservation of momentum
m x 7.67 = ( m + 2m ) v
= 3m v
v = 2.55 m /s
In perfectly inelastic collision , mechanical energy is not conserved.
Initial kinetic energy
= 1/ 2 x m x v²
= .5 x m x 58.8
= 29.4 m
Kinetic energy after collision
= .5 x 3m x (2.55) ²
= 9.75375 m
Loss of kinetic energy
= 19.646 m
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