Question

The fastest pitched baseball was clocked at 46 m/s. assume that the pitcher exerted his force (assumed to be horizontal and constant) over a distance of 1.0 m, and a baseball has a mass of 145 g.

Answer 1

Using the Equation:
                                 v² = vi² + 2 · a · s    → Eq.1
where,
v = final velocity 
vi = initial velocity 
a = acceleration 
s = distance 

We know that vi = 0 because the ball was at rest initially.

Therefore,

Solving Eq.1 for acceleration,
 
 v² = vi² + 2 · a · s
 v² = 0 + 2 · a · s
 v² = 2 · a · s
Rearranging for a,
a = v ²/2·s
Substituting the values,
a = 46²/2×1 
a = 1058 m/s² 

Now applying Newton's 2nd law of motion,
 
F = ma
   = 0.145×1058

F = 153.4 N