Inclined Planes with Wheels and Axles

The longer the ramp, the less force we need.  Wheels and axles help us overcome friction.

Students used spring scales to measure the amount of force required to lift weights to a height of 1 foot.  They then measured the amount of force to drag the object up ramps of varying lengths (2, 3 or 4 feet) to reach the height of one foot.

We found that the longer the ramp, the less force we needed, but the total energy required (force X distance) was way more on the ramps.  We also measured the force to drag the weight over a flat surface.  We found when we subtracted this force from the force needed to pull the weight up the ramp, the energy required for all methods was about the same.

One group had a toy truck as their weight.  They found that their friction was near zero and that the energy needed to go up the ramps (force X distance) was about the same using all ramps and it was about the same as lifting the truck straight up.

Ramps help us raise objects by lessening the amount of force we need to apply to the object to move it, but we have to move it a greater distance.