PLEASE HELP ASAP A ball is rolling on a flat, frictionless surface. What will happen to the ball if no unbalanced force acts on the ball? A.
The ball will roll faster and faster.

B.
The ball will begin to roll in the opposite direction.

C.
The ball will begin to roll faster for a time and then begin to roll slower.

D.
The ball will continue to roll in the same direction and at the same speed.

An air standard cycle with variable specific heats is executed in a closed system and is composed of the following four processes. 1-2 isentropic compression 100 kpa and 22°c to 600 kpa 2-3 v=constant heat addition to 1500 k 3-4 isentropic expansion to 100 kpa 4-1 p=constant heat rejection to initial state (a) show the cycle on p-v and t-s s (b) calculate the net work output per unit mass (409 kj/kg) (c) determine the thermal efficiency (47.9%)