Question

Shawn and his bike have a total mass of

52.3 kg. Shawn rides his bike 1.6 km in
17.4 min at a constant velocity.
The acceleration of gravity is 9.8 m/s
2
.
What is Shawn’s kinetic energy?

Answer 1

Shawn's kinetic energy is 61.45 J.

Step-by-step explanation:

Given;

Mass of the system is,
`m=52.3\ kg`

Displacement of the bike is,
`d=1.6\ km=1.6* 1000=1600\ m`

Time taken is,
`t=17.4\ min=17.4* 60=1044\ s`

Let the constant velocity be
`v`.

For constant velocity, magnitude of velocity is given as distance by time.

Therefore,
`v=(d)/(t)=(1600)/(1044)=1.533\ m/s`

Now, kinetic energy of a body is given as:

`KE=(1)/(2)mv^2`

Here,
`m=52.3\ kg,\ v=1.533\ m/s`

`\therefore KE=(1)/(2)* 52.3* (1.533)^2\\KE=0.5* 52.3* 2.35\\KE=61.45\ J`

Therefore, Shawn's kinetic energy is 61.45 J.