Relativistic Baseball Calculate the magnitude of the force required to give a 0.145-kg baseball an acceleration a

Question:

Relativistic Baseball Calculate the magnitude of the force required to give a 0.145-kg baseball an acceleration a = 1.00 m/S' in the direction of the baseball's initial velocity when this velocity has a magnitude of
(a) 10.0 m/s;
(b) 0.900c;
(c) 0.990c.
(d) Repeat parts (a), (b), and (c) If the force and acceleration are perpendicular to the velocity.