Question

A 27 g ball is fired horizontally with speed v₀ toward a 106 g ball hanging motionless from a 1.13-m-long string. The balls undergo a head-on, perfectly elastic collision, after which the 106 g ball swings out to a maximum angle θ_max=57^°. What was v₀?

Answer 1

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Let

First find velocity of m₂ after collision

after collision kinetic energy of m₂ is converted to potential energy

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Since the collision is elastic both momentum and energy is conserved

Consider conservation of momentum

momentum before collision =momentum after collision

-----------------(1)

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Consider conservation of energy

kinetic energy before collision =kinetic energy after collision

Put (1) in above equation

ANSWER:

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