Only one force acts on an object, can the object have zero acceleration? can the object have zero velocity? explain.

If a sphere and a cure have the same mass and are propelled up a ramp with the same force, which would travel father up the ramp? explain.

Arocket starts from rest and moves upward from the surface of the earth. for the first 10.0 s of its motion, the vertical acceleration of the rocket is given by ay = 12.80 m/s32t, where the +y-direction is upward. (a) what is the height of the rocket above the surface of the earth at t = 10.0 s? b) what is the speed of the rocket when it is 325 m above the surface of the earth?

For the car in the picture ,in which direction is the normal force? -into the screen -down -out of the screen -up