On a typical clear day, the atmospheric electric field points downward and has a magnitude of approximately 119 N/C. Compare the gravitational and electric forces on a small dust particle of mass 3.3 ✕ 10−15 g that carries a single electron charge.

Aferris wheel is a vertical, circular amusement ride with radius 9 m. riders sit on seats that swivel to remain horizontal. the ferris wheel rotates at a constant rate, going around once in 9 s. consider a rider whose mass is 56 kg. at the bottom of the ride, what is the perpendicular component of the rate of change of the rider's momentum? at the bottom of the ride, what is the vector force exerted by the seat on the rider?

When the force acting on an object points at least partially in the direction of the motion the work done is considered to be negative

Imagine that someone pushes one marble toward a motionless marble. would there still be action-reaction forces involved in the collision? how might the marbles’ motions be changed? ?