Q. 184.3( 128 Votes )

# How much momentum will a dumb-bell of mass 10 kg transfer to the floor if it falls from a height of 80 cm? Take its downward acceleration to be 10 m s^{-2}.

Answer :

Firstly, we will calculate the final velocity:

Given,

Initial velocity, u = 0 (As it falls from rest)

Final velocity, v =?

Acceleration, a = 10 ms^{2}

And, Distance, s = 80 cm

= m

= 0.8 m

We know that,

v^{2} = u^{2} + 2as

v^{2} = (0)^{2} + 2 × 10 × 0.8

v^{2} = 16

v =

= 4 m/s

Momentum = Mass × Velocity

= 10 ×4

= 40 kg m/s

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