Classical Mechanics
# Potential Energy

An object of mass $4\text{ kg}$ lies on the ground. If the object is lifted up $20\text{ m},$ what is the work done by gravity?

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

$m=2\text{ kg}$ initially at rest at the peak of a frictionless inclined plane that makes a $30^\circ$ angle with the horizontal, slides all the way down the ramp. If the initial height of the block was $h=50\text{ m},$ what is the total work done on the block by gravity?

A block of massAn object of mass $9\text{ kg}$ moves on a horizontal floor at $4\text{ m/s}.$ If the object moves a total of $50\text{ m},$ what is the work done by gravity to the object?

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