3.2.1 Intro to Work and Energy

Example 1: No Motion

•A student is trying to push a heavy crate across the floor, but it does not move. 

–Is work being done ‘on the crate’?

​Example 2: A box is pushed with a force of 100 newtons across a frictionless surface for a distance of 10 meters. 

–How much work is done on the box?

​Example 4: A sled is pulled a horizontal distance of 4.0 meters across a frictionless surface using a force of 15 newtons at an angle of 30° above the horizontal. 

–How much work is done on the sled?

•A 300N for is required to hold a 50N box in place on a 5m long ramp at an incline of 25 degrees. How much work is done by holding the box in place?

•Which graph best represents the greatest amount of work?