as a baseball is being caught, its speed goes from 30.0m/s to 0.0m/s in about 0.0050 s.?

Question

the mass of the baseball is 0.145 kg.
a) what are the baseball's acceleration?
b) what are the magnitude and direction of the force acting on it?
c) what is the magnitude and direction of the force acting on the player who cauight it?

Answer 1

a)
Assuming the acceleration is constant (and therefore, the force acting on it is also constant) over the time it is being caught:
a = (change in velocity) / (the time it took)
a = (-30 m/s) / (0.005 s)
a = 6000 m/s^2

b)
F = (mass)*(acceleration)
F = (0.145 kg) * (6000 m/s^2)
F = 870 N

c)
The magnitude is 870 N. The direction is along the trajectory of the ball right before it was caught.

Answer 2

a) v=u+at
0=30+a(0.005)
a=-30/0.0050
a=-6000m/s^2
b)F=Ma
F=0.145*(-6000)
=-870N (downward direction)
c)Same as b=-870N (also downward direction)