Question

1. At what speed do a bicycle and its rider, with a combined mass of 100 kg, have thesame momentum as a 1500 kg car traveling at 5.0 m/s?

Answer 1

We will ave the following:

First, we calculate the momentum of the car:

$\rho=(1500\operatorname{kg})(5.0m/s)\Rightarrow\rho=7500kg\cdot m/s$

Now, we will determine the speed of the bike rider:

$7500\operatorname{kg}\cdot m/s=100\operatorname{kg}\cdot v\Rightarrow v=\frac{7500\operatorname{kg}\cdot m/s}{100\operatorname{kg}}$$\Rightarrow v=75m/s$

So, the bike rider would have to be moving at 75 m/s. [About 270 km/h]