Question

A 50 kg pitcher throws a baseball with a mass of 0.15 kg. If the ball is thrown with a positive velocity of 35 m/s and there is no net force on the system, what is the velocity of the pitcher? −0.1 m/s −0.2 m/s −0.7 m/s −1.4 m/s

Answer 1

the answer is -0.1 m/s if you're looking for the Edgnuity answer. I just took the test. Hope this helps!

Answer 2

The velocity of the pitcher is −0.1 m/s

Explanation:

Given : Mass of pitcher = 50 kg

Mass of Baseball= 0.15kg

Velocity of Ball = 35m/s

To Find : velocity of the pitcher

Solution :

The total momentum of the system is conserved when no external force acts on a system .The total initial momentum of the system is equal to the total final momentum of the system.

Since , the ball and the pitcher are initially at rest, therefore, the total initial momentum of the system is zero.

Since we are given that no external forces act on the system , the total final momentum of the system is also equal to zero.

Let us suppose the mass of the pitcher is
`m_(p)`

Speed of pitcher =
`v_(p)`

The mass of the ball is
`m_(b)`

Speed of ball =
`v_(b)`

So, the final momentum of the system of pitcher and the ball is given by:

`momentum =m_(p) v_(p) +m_(b) v_(b) =0`

⇒
`50* v_(p) +0.15*35 =0`

⇒
`50* v_(p) +5.25 =0`

⇒
`v_(p) = (-5.25)/(50)`

⇒
`v_(p) = -0.105`

Thus , The velocity of the pitcher is -0.105m/s≈−0.1 m/s

Negative sign shows the opposite direction.

Hence The velocity of the pitcher is −0.1 m/s