SOLUTION: 5. The energy of a moving body varies directly as the square of its speed. If a body has energy of 5 units at a speed of 3 feet per second, what is its speed when its energy is 20
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Question 1174188: 5. The energy of a moving body varies directly as the square of its speed. If a body has energy of 5 units at a speed of 3 feet per second, what is its speed when its energy is 20 units? (show complete solution thanks!) Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! E=k*s^2
5=k*3^2
k=(5/9)
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Now use k in the next equation
20=(5/9)*s^2
s^2=20(9/5)=36 units
s=6 units
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Can check this by noting that speed doubled from 3 ft/sec to 6 ft/sec and energy therefore should quadruple from 5 units to 20 units.
