Question

A weightlifter holds a 1,300 N barbell 1 meter above the ground. One end of a 2-meter-long chain hangs from the center of the barbell. The chain has a total weight of 600 N. How much work (in J) is required to lift the barbell to a height of 2 m?

Answer 1

Answer: 1750J

Explanation:

The work done that will be used to loft the barbell and the hanging chain will be:

W1 = (1300 + (1/2 × 600))

= 1300 + 300

= 1600J

The work done that'll be used in lifting the upper part of the chain will be:

W2 = (1/2 × 600) × (1/2 × 1).

= 300 × 0.5

= 150J

Total work down will be:

=W1 + W2

= 1600J + 150J

= 1750J