Question

3. Car tires are sometimes “balanced” on a machine that pivots the tire and wheel about the center. Weights are placed around the wheel rim until it does not tip from the horizontal plane. Discuss this procedure in terms of the center of gravity.

Short answer

The car tires are balanced because the net torque is zero.

Step-by-step solution

center of gravity

The center of gravity is the point on a body where the total weight of the body is concentrated.

Net torque is zero

The center of gravity of a wheel can be displaced which results in an unwanted torque.

To balance the displaced weight, additional weight is added in order to replace the center of gravity.

Therefore, the zero net torque balances the car tires.