Can a Seventh grader push a 1500 kg automobile? If they can overcome the friction between the tires and the road, they can!
Friction takes many forms. The students investigated the difference between Static Friction and Rolling friction. It was impossible to SLIDE the car across the parking lot when the parking break was on, because the force of Static Friction was too great to overcome. Rolling Friction however is smaller than Static Friction, and was easily overcome when the car was allowed to ROLL on its tires. When the forces of friction and pushing were balanced, the car did not move. When these forces were unbalanced, the car’s motion changed.