Question

Which of the following situations satisfies both the first condition for equilibrium (net force = 0) and the second condition for equilibrium (net torque = 0)?

A) a thrown baseball that rotates as it moves through the air as a projectile (speed changes)

B) an automobile crankshaft turning at an increasing angular speed in the engine of a parked car

C) none of these

D) an airplane taking off (speed increases)

Answer 1

None of these

A projectile will experience gravitational force.

In the remaining cas3s, the speed 8s increasing, so acceleration is not zero. Thus there will be some force on the bodies.