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Power = F v. If you want to double the speed of a car, by what factor must you increase the power of the engine? (Note: this is why cars can't go 500 mph)

User Jrara
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To double the speed of a car, you must increase the power of the engine by a factor of four due to the quadratic relationship between power, force, and velocity in the formula Power=Fv.

The relationship between power (P), force (F), and velocity (v) is given by the formula P=Fv. This equation indicates that power is directly proportional to both force and velocity. When seeking to double the speed of a car, one might consider only doubling the power required. However, due to the quadratic nature of the power equation, the impact on velocity is more significant.

If you want to double the speed of the car, the velocity term (v) in the power equation becomes 2v. Therefore, the new power requirement (Pnew) is given by Pnew​ =F×2v. Simplifying this expression yields

Pnew=2×F×v, indicating that to double the speed, the power must be increased by a factor of four (2 squared). This relationship illustrates why achieving extremely high speeds, such as 500 mph, requires a disproportionately large increase in engine power, making it impractical for many vehicles.

User Jstacks
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