Can you reduce friction by decreasing the weight of the object on
top? For example, if you wanted to reduce the friction between the
tires of a car and the ground underneath it. Let's say on the first
test the cars total weight was 3500 lb, if we took out unnecessary
items would it reduce the friction between the tires and the ground
on the second test? Considering that weight is the gravitational
force exerted on an object and by decreasing the force or the push
thus reducing friction between the two objects.
Friction force = coefficient of friction times the support force.
You can test this with a spring scale pulling on a wood plank. You
can change the support force by adding weights on top of the
plank. You will see a difference in the frictional force on the
scale as you pull at a constant velocity.
Click here to return to the Physics Archives
Update: June 2012