# What is the maximum attainable speed for the car?

## Homework Statement

P62 Sterling. #11
A new design for a car is to have a large disc like flywheel within the car storing kinetic energy. The flywheel has a mass of 370 kg witha radius of 0.5 meters and can rotate up to 200 revolutions a second. Assuming all of this store kinetic energy can be transferred to the linear velocity of the 1500 kg car what is the maximum attainable speed of the car?

KE=(mv^2)*1/2

## The Attempt at a Solution

I calculated the circumference of the wheel to be 3.14 m. If there are 200 revolutions per second then the wheel travels 628 m/s ( velocity of the wheel) . Using KE=(mv^2)*1/2, the kinetic energy is 7.3*(10^7)joules for the wheel.
Is the amount of energy that should be transferred to the 1500 kg car. 7.3*(10^7)joules = 1500(v^2 )*1/2. But the answer for velocity (4.7 *10^5)m/s I get is incorrect. It seems like this should work but it does not it seems like this should work but it does not. Why not?

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