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Mekhanik [1.2K]
3 years ago
7

A 71.5 kg football player is gliding across very smooth ice at 2.00 m/s . He throws a 0.470 kg football straight forward. What i

s the player's speed afterward if the ball is thrown at 12.5 m/s relative to the ground? Express your answer with the appropriate units
Physics
1 answer:
polet [3.4K]3 years ago
6 0

Answer:

The player's speed is 1.93 m/s.

Explanation:

Given that,

Mass of football = 71.5 kg

Speed = 2.00 m/s

Mass of football = 0.470 Kg

Speed = 12.5 m/s

We need to calculate the initial momentum of the football player and ball

P_{i}=(m+m_{b})v_{i}

Put the value into the formula

P_{i}=(71.5+0.470)\times2.00

P_{i}=143.94\ kg-m/s

We need to calculate the final momentum of the system

P_{f}=mv+m_{b}v_{b}

Put the value into the formula

P_{f}=71.5\times v+0.470\times12.5

P_{f}=71.5\times v+5.875

We need to calculate the relative to the ground

Using conservation of momentum

P_{i}=P_{f}

Put the value into the formula

143.94=71.5\times v+5.875

v=\dfrac{143.94-5.875}{71.5}

v=1.93\ m/s

Hence, The player's speed is 1.93 m/s.

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