Question

During a circus act, an elderly performer thrills the crowd by catching a cannon ball shot at him. The cannon ball has a mass of 72.0 kg and its horizontal component of velocity is 6.50 m/s just before the 65.0 kg performer catches it. If the performer is initially motionless on nearly frictionless roller skates, what is his speed immediately after catching the cannon ball

Answer 1

3.416 m/s

Step-by-step explanation:

Given that:

mass of cannonball
`m_A` = 72.0 kg

mass of performer
`m_B` = 65.0 kg

The horizontal component of the ball initially
`\mu_(xA)` = 6.50 m/s

the final velocity of the combined system v = ????

By applying the linear momentum of conservation:

`m_A \mu_(xA)+m_B \mu_(xB) = (m_A+m_B) v`

`72.0 \ kg * 6.50 \ m/s+65.0 \ kg * 0 = (72.0 \ kg+65.0 \ kg) v`

`468 kg m/s + 0 = (137 kg)v`

`v = (468\ kg m/s )/(137 \ kg)`

v = 3.416 m/s