Tim and his younger brother are playing with toy cars and a ramp. His brother tries to park his car when the car is facing downward on the ramp. It doesn’t work and the car rolls down the ramp on its own. Tim explains the problem using Newton’s first law of motion. What would Tim say is necessary for an object to remain at rest? There must be a gravitational pull on the object.
The forces acting on the object must be balanced.
The forces acting on the object must be unbalanced.
There must be a greater upward force acting on the object.