A hockey ball of mass 200 g travelling at 10 ms ^{–1 }is struck by a hockey stick so as to return it along its original path with a velocity at 5 ms ^{–1} . Calculate the magnitude of change of momentum occurred in the motion of the hockey ball by the force applied by the hockey stick.

Asked by Vishal kumar | 2 years ago | 329

Given, the mass of the

ball (m) = 200g

Initial velocity of the ball (u) = 10 m/s

Final velocity of the ball (v) = 5 m/s

Initial momentum of the ball = mu = 200g × 10 ms-1 = 2000 g.m.s^{-1}

Final momentum of the ball = mv = 200g × 5 ms^{-1} = 1000 g.m.s^{-1}

Therefore, the change in momentum (mv – mu) = 1000 g.m.s^{-1 }- 2000 g.m.s^{-1} = -1000 g.m.s^{-1}

This implies that the momentum of the ball reduces by 1000 g.m.s^{-1} after being struck by the hockey stick

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Time (seconds) |
Distance (meters) |

0 | 0 |

1 | 1 |

2 | 8 |

3 | 27 |

4 | 84 |

5 | 125 |

6 | 216 |

7 | 343 |

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**(b)** What do you infer about the forces acting on the object?

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