A1.8 kg baseball bat is swinging at 42m/s. it hits a 0.2 kg baseball. after the collision, the bat continues at 28 m/s.

Explanation:

The missing question her is: What is the change in momentum of the baseball?

According to the Impulse-Momentum Theorem, we have:

Where:

is the exerted force

is the time interval

is the change in momentum

So, in the case of the bat and the ball we have:

For the bat:

(1)

For the ball:

(2)

Since is the same for both the bat and the ball, their impulses are equal in magnitude but in opposite direction according to Newton's 3rd law of motion. Hence:

(3)

Then:

 (4)

Where:

Being , ,

Being

Then (4) is rewritten as:

 (5)

Since :

 (6)

Isolating :

(7)

(8)

(9)

Now, the change in momentum of the baseball is:

(10)

Substituting (9) in (10):

(11)

Finally:

This is the change in momentum of the baseball. Note it is negative because its initial velocity is greater than its final velocity

because growing process had stoped after 4-5 year