Which of these follows from newton's laws about the energy of a moving object? a)the total mechanical energy of an object is always constant. b)the kinetic energy of an object remains the same if friction is absent. c)the mechanical energy remains the same if there are only conservative forces acting. d)the total of all forms of energy is always constant.

What is created when solids,liquids,an gases mix with one another

Aballoon is rising vertically upwards at a velocity of 10m/s. when it is at a height of 45m from the ground, a parachute bails out from it. after 3s he opens his parachute and decelerates ata a constant rate 5m/s.when. (a) what was the height of the parachutist above the ground when he opened his parachute? (b)how far is the parachutist from the balloon at t=3s? (c)with what velocity does the parachutist hit the ground? (d)after how long does the parachutist hit the ground after his exist from the balloon?

You are standing on a boat. which of the following strategies will make the boat start moving? a. pushing the mast b. throwing some cargo out of the boat c. pushing the front ofthe boat d. pushing another passenger