14.1 Work and Power
14.2 Work and Machines
14.3 Mechanical Advantage and Efficiency
14.4 Simple Machines
How Do Ramps Help You Raise Objects?
Procedure
Make a stack of five books.
Make a ramp by leaning a short board against the top of the book stack. Place a sixth book against the bottom edge of the board to keep the ramp from sliding down.
Measure and record the height and length of the ramp.
Use a spring scale to pull a laboratory cart up the ramp at constant speed. Record the force indicated on the spring scale.
Repeat Steps 2 through 4 using a longer board.
Think About It
Comparing and Contrasting Which ramp required a greater force to pull the cart? Which ramp required the cart to travel a greater distance?
Predicting How do you think the force needed to pull the cart would change if the cart accelerated up the length of the ramp?
Formulating Hypotheses Explain why a box that is too heavy to lift can often be pushed up a ramp.