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

Answer:

3.416 m/s

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:

$m_A \mu_{xA}+m_B \mu_{xB} = (m_A+m_B) v$

$72.0 \ kg \times 6.50 \ m/s+65.0 \ kg \times 0 = (72.0 \ kg+65.0 \ kg) v$

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

$v = \dfrac{468\ kg m/s }{137 \ kg}$

v = 3.416 m/s