Question

Taleni and his brother Taleiko have a combined mass of 200kg and are zooming along 1 × 10^5 g amusement park bumper car at 10.0 m/s. They bump Martha's car which has the same mass as theirs which is sitting still. Martha has a mass of 25.0 kg. after the collision the brother continued ahead with a speed of 4.12 m/s. how fast is Martha's car bumped across the floor?

Answer 1

From the conservation of momentum:

$$m_1v_1=m_1v_1'+m_2v_2$$

$$(300)(10)=(300)(4.12)+(125)v_2$$

$$v_2=14.1\frac{m}{s}$$