Question

Tony (of mass 70 kg) coasts on his bicycle (of mass 20 kg) at a constant speed of 7 m/s, carrying an 8 kg pack. Tony throws his pack forward, in the direction of his motion, at 4 m/s relative to the speed of bicycle just before the throw. What is the initial momentum of the system (Tony, the bicycle, and the pack)?

Answer 1

Answer:686 kg-m/s

Step-by-step explanation:

Given

mass of tony
`m_1=70 kg`

mass of bicycle
`m_2=20 kg`

mass of pack
`m_3=8 kg`

Speed of tony
`v=7 m/s`

Tony throw a pack at 4 m/s relative to the speed of bicycle

`Momentum= mass* velocity`

Bike, tony and Pack have the same velocity v=7 m/s before the throw

Momentum just before throw is

`P_(initial)=(m_1+m_2+m+3)\cdot v`

`P_(initial)=(70+20+8)\cdot 7=686 Kg-m/s`