Question

A 19 kg child is riding a 5.6 kg bike with a

velocity of 5.0 m/s to the northwest.
a) What is the total momentum of the child
and the bike together?
Answer in units of kg. m/s.
What is the momentum of the child?
Answer in units of kg. m/s.
c) What is the momentum of the bike?
Answer in units of kg. m/s

Answer 1

`\mathrm{a.\:}123\:\mathrm{kg\cdot m/s},\\\mathrm{b.\:}95\:\mathrm{kg\cdot m/s},\\\mathrm{c.\:}28\:\mathrm{kg\cdot m/s}`

Step-by-step explanation:

The momentum of an object is given by:

`p=mv`, where
`m` is the mass of the object and
`v` is the velocity of the object.

a)

The mass of the child and bike together is
`19+5.6=24.6` kilograms. Since they're moving at a velocity of 5.0 m/s, their momentum is:

`p=24.6\cdot 5=\fbox{$123\:\mathrm{kg\cdot m/s}$}`.

b)

The mass of the child is given as 19 kg. Since the child is on the bike moving at 5.0 m/s, it's implied the child is as well. Therefore, the momentum of the child is:

`p=19\cdot 5=\fbox{$95\:\mathrm{kg\cdot m/s}$}`.

c) The mass of the bike is given as 5.6 kg and it is moving at 5.0 m/s. Therefore, the momentum of the bike is:

`p=5.6\cdot 5=\fbox{$28\:\mathrm{kg\cdot m/s}$}`