JIPMER 2019 Morning Papers Online Practice

(1)
The velocity attained by the ball before hitting the ground = √2gh = √2×10×20 20m/ s(-

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)
As ball bounce back to the same height it means collision is elastic so velocity just after hitting the ground = 20m/ s(+

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)
So, change in velocity = vf–vi = 20 – (– 20) = 40

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m/ s
Force =

ΔP

Δt

=

mvt−mv1

Δt

=

m(vt−v1)

Δt

=

0.1×40

0.04

=100N

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