Physics Review Question Unit: Work and Energy Year: 1994 Question#: 20 Question: A force of 0.2 newton is needed to compress a spring a distance of 0.02 meter. The potential energy stored in this compressed spring is (1 ) 8 x 10-5 J (2 ) 2 x 10-3 J (3 ) 2 x 10-5 J (4 ) 4 x 10-5 J What is this question really asking? Explanation by: Jay D [ Return to question menu ] Answer 1 8 x 10-5 J INCORRECT This one is wrong. The formula that should have been used is: Pes=1/2kX2 In order to use this formula you need to find k. k=F/X k=.2N/.02m so k=10N/m return to top Answer 2 2 x 10-3 J CORRECT The formula to use is PEs=1/2kX2 In order to use this formula you need to find k. k=F/X k=.2N/.02m so k=10N/m PEs=1/2(10N/m)(.02m/s2) PEs=2 x 10-3 J return to top Answer 3 2 x 10-5 J INCORRECT Your on the right track but check the exponent. return to top Answer 4 4 x 10-5 J INCORRECT The formula to use is PEs=1/2kX2 In order to use this formula you need to find k using F = kx return to top What's this question really asking? How much potential energy is stored in a compressed spring? return to top |
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