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laylay918
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Homework Statement
Investigate the amount of kinetic energy involved when your car's speed is 60 km/h, 50 km/h, 40 km/h, 30 km/h, 20 km/h, and 10 km/h. (Find your car's mass in the owner's manual) How much work does the brake system have to do to stop the car at each speed?
Homework Equations
KE = 1/2 mv^2
The Attempt at a Solution
I figured out the KE for each of those speeds for a 1500 kg car. The problem is the second portion of the question. How much work does the brake system have to do to stop the car at each speed? I have no idea how to solve that part because no equations are given. Anyways, here is my work for the first portion.KE = 1/2(1500kg)(60km/h)^2 = 2,700,000 J
KE = 1/2(1500kg)(50km/h)^2 = 1,875,000 J
KE = 1/2(1500kg)(40km/h)^2 = 1,200,000 J
KE = 1/2(1500kg)(30km/h)^2 = 675,000 J
KE = 1/2(1500kg)(20km/h)^2 = 300,000 J
KE = 1/2(1500kg)(10km/h)^2 = 75,000 J