car moves 4 times as fast as another identical car.Compared to the slower car.Thefaster car has__ time the KE?

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car moves 4 times as fast as another identical car.Compared to the slower car.Thefaster car has__ time the KE?

A. 2
B. 4
C. 8
D. 16

Please help it'll me so much to me

A machine puts out 100 W of power for every 1000 W put into it. the efficiency of the machine is:

A. 10%
B. 50%
C. 90%
D. 110%

2007-05-23 01:30:29 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Physics

3 answers

KE = 0.5mv^2, so multiplying v by 4 increases KE by a factor of 4^2 = 16. D) 16

Effeciency is a simple ratio. E = 100%*(output/input) = 100%*(100/1000) = 100%*0.1 = 10%, A) 10%

2007-05-23 01:32:38 · answer #1 · answered by DavidK93 7 · 1⤊ 0⤋

how r u

1-16

2- 10%

2007-05-23 08:38:19 · answer #2 · answered by Anonymous · 0⤊ 0⤋

Not much more to say. First answer is correct and well described. Super!!!!!!!

2007-05-23 08:43:10 · answer #3 · answered by Geoff_and_Katie 2 · 0⤊ 0⤋