A satellite of mass 850 kg is in a circular orbit around the Earth, if the satellite is moving at 1,140 m /s and the Earth’s gravity is exerting a force on the satellite of 3.61 N, what is the radius of the satellite’s orbit? a. 1.61x10 8m b. 3.06x10 8m c. 8.11x10 8m d. 1.02x10 9m

we need to know the time interval during which the force acts. impulse of force = momentum change

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.