How do i do this question. A weightlifter lifts a 32 kg set of weights from ground level to position over the head. The vertical lift is 2.2 m. How much work does the weightlifter do
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Expert's answer
2013-03-04T08:50:01-0500
Let's write the law conservation of energy(the work which the weightlifter do will equal to difference between initial and final potential energies): A = U2 - U1 A - work which the weightlifter do, U1, U2 - initial and final potential energies U = mgh - the definition of the potential energy m - mass g - gravitational acceleration h - high At the beginning, the weightlifter was staying on the ground, so h=0. A = mgh - mg*0 = mgh A = 32*2.2*9.8 = 689.92 J Answer: 689.92 J
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