Question

Andrea rides her bicycle at a speed of 10 m/s. She and the bike have a combined mass of

50 kg.
a.
If she uses her brakes to slow down to 5 m/s, how much energy is converted to
heat?

Answer 1

1875 J of energy is converted to heat.

Step-by-step explanation:

Given that,

The combined mass of Andrea and the bike is 50 kg

Initial speed of Andrea's bicycle, u = 10 m/s

Final speed of Andrea's bicycle, v = 5 m/s

The energy converted to heat can be calculated using the work-energy theorem as follows :

`E=(1)/(2)m(v^2-u^2)\\\\E=(1)/(2)* 50* ((5)^2-(10)^2)\\\\E=-1875\ J`

So, 1875 J of energy is converted to heat.