A13-kg (including the mass of the wheels) bicycle has 1-m-diameter wheels, each with a mass of 3.1 kg. the mass of the rider is 38 kg. estimate the fraction of the total kinetic energy of the rider-bicycle system is associated with rotation of the wheels?

Explanation:

Linear kinetic energy of the bicycle is given as

Now rotational kinetic energy of the wheels

now kinetic energy of the rider is given as

So we have

acceleration = (change in speed) / (time for the change)

change in speed = (20-120)= -100 m/s.

1.5 min = 90 sec

acceleration = -100/90 = -1.11 m/s^2.

we don't care about the 150kg or the 2,500 meters. they don't make any difference.

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