 Classical Mechanics

# Momentum of an object

A $69\text{ kg}$ stuntman jumps out of a window and lands on a trampoline $5\text{ m}$ below. What is the magnitude of his momentum at the point he hits the trampoline?

Assumptions

• The air resistance is negligible
• The gravitational acceleration is $g=10\text{ m/s}^2.$

An object of mass $4\text{ kg}$ is thrown straight upward into the air at a velocity of $15\text{ m/s}$ from the edge of a cliff. Let $p_1$ be the momentum of the object $1$ second after the throw, and $p_{4}$ the momentum of the object $4$ seconds after the throw. Then what is $\displaystyle{\frac{p_{4}}{p_1}}?$

Assume that gravitational acceleration is $g=10\text{ m/s}^2.$

Two objects $A$ and $B$ are moving on the ground in the same direction at $5\text{ m/s}$ and $2\text{ m/s},$ respectively. Their respective masses are $3\text{ kg}$ and $4\text{ kg}.$ Now, they both start to accelerate uniformly at $-3\text{ m/s}^2$ and $0.5\text{ m/s}^2,$ respectively, at the same time. Four seconds after that, what is the sum of their linear momenta?

A $1\text{ kg}$ ball is rolling on the floor at $4\text{ m/s}.$ Find the momentum of the ball.

An object initially at rest falls freely in an atmosphere free of air resistance. After $t$ seconds, the kinetic energy of the object is $x\text{ J}$ and the momentum of the object is $y\text{ kg}\cdot{m/s}.$ If $x=y,$ what is the value of $t?$

Assume that gravitational acceleration is $g=10\text{ m/s}^2.$

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