E = ke = (1/2) m v^2
that goes into the brake pads and into the water heating both up to T
(1/2)1500 (400) = 4200*8.5 (T-20)+ 890*4(T-25)
A 1500 kg car is travelling at 20 m/s. It brakes to a stop causing the brake pads to heat up from 25 degrees Celsius to a temperature too hot to touch. The total mass of the pads altogether is 4.0 kg and their heat capacity is 8.9 x 102
J/kg0C. If these pads are removed from the car while hot and put into a bucket containing 8.5 kg of water at 20 0C,what final temperature will the water reach? (Assume all the energy transfers are 100% efficient.) The heat capacity
of water is 4.2 x 103 J/kg0C.
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