 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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