Question

Without the wheels, a bicycle frame has a mass of 6.71 kg. Each of the wheels can be roughly modeled as a uniform solid disk with a mass of 0.820 kg and a radius of 0.343 m. Find the kinetic energy of the whole bicycle when it is moving forward at 3.22 m/s.

Answer 1

Answer:43.311 J

Explanation:

Given

mass of frame$\left ( m_f\right )=6.71 kg$

mass of  wheel $\left ( m_w\right )=0.820 kg$

radius of wheel$\left ( r\right )=0.343 m$

v=3.22 m/s

Moment of inertia of each wheel\left ( I\right )=\frac{1}{2}mr^2[/tex]

$I=0.0482 kg-m^2$

kinetic Energy of whole cycle=Kinetic energy of wheels and frame+rotational energy of Wheels

$K.E.=\frac{1}{2}\left ( m_f+m_w\right )v^2+2\times \frac{1}{2}I\omega ^2$

$K.E.=\frac{1}{2}\left ( 6.71+0.820\right )3.22^2+2\times \frac{1}{2}0.0482\times \left ( \frac{3.22}{0.343}\right )^2$

K.E.=39.037+4.274=43.311J