Classical Mechanics

# Impulse of a constant force

A $$66\text{ kg}$$ stuntman jumps out of a window that's $$5\text{ m}$$ above the ground. When he hits the ground, the impulse time between him and the ground is $$2\text{ s}.$$ What is the average force delivered to the man by the ground during the impulse?

Ignore any air resistance, and assume that gravitational acceleration is $$g=10\text{ m/s}^2.$$

An object of mass $$0.5\text{ kg},$$ initially at rest, acquires a speed of $$2\text{ m/s}$$ after being pushed by a constant force $$F.$$ If the impact time is $$25\text{ ms},$$ what is the magnitude of $$F?$$

An object of mass $$m$$ traveling horizontally with velocity $$v$$ strikes a massive vertical wall and rebounds back along its original direction with no change in speed. If the impulse time is $$2\text{ ms},$$ what is the magnitude of the force delivered by the wall to the object?

A man playing pocket-ball strikes the white ball with mass $$0.5\text{ kg},$$ and the ball gets a launch speed of $$10\text{ m/s}.$$ If the strike delivered a constant force of magnitude $$25\text{ N},$$ what is the impulse time?

A ball of mass $$1\text{ kg}$$ is dropped straight downward from a $$20\text{ m}$$ high rooftop. After the ball hits the ground, it bounces back in the air up to $$5\text{ m},$$ and then starts to fall again. If the impact time between the ball and the ground is $$50\text{ ms},$$ what is the magnitude of the average force exerted by the ground on the ball?

Ignore any air resistance, and assume that gravitational acceleration is $$g=10\text{ m/s}^2.$$

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