Question

A baseball weighs 5.13 oz. what is the kinetic energy, in joules, of this baseball when it is thrown by a major league pitcher at 95.0 mi/h

Answer 1

Let's convert all the quantities into S.I. units:
Mass of the ball: $m=5.13 oz=0.15 kg$
Speed of the ball: $v=95.0 mi/h=42.5 m/s$

The kinetic energy of the ball is given by
$K= \frac{1}{2}mv^2$
where m is the mass and v the speed. Substituting the data of the problem, we find
$K= \frac{1}{2}(0.15 kg)(42.5 m/s)^2=135.5 J$

Answer 2

Answer:

409.4 joule

Explanation:

First convert oz into kg

1 oz = 0.0283495 kg

So, 5.13 oz = 0.1454 kg

Now convert mi/h into km/h.

1 mi/h = 0.447 m/s

So, 95 mi/h = 42.468 m/s

Now use the formula for kinetic energy

K.E = 0.5 x m v^2

     = 0.5 x 0.454 x 42.468 x 42.468

     = 409.4 Joule