Question

A weightlifter holds a 1,500 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 400 N. How much work (in J) is required to lift the barbell to a height of 2 m

Answer 1

1800 J

Step-by-step explanation:

We are given that

Weightlifter hold weight, w=1500N

Height of weightlifter from ground,h=1m

Length of chain=2m

Total weight of chain, w'=400 N

We have to find the work done required to lift the barbell to height of 2m.

Total work done=Work done to lift a barbell and half of the chain+ work done to lift the upper half of the chain

Total work done=
`1500+(1)/(2)(400)+(1)/(2)(400)((1)/(2)(1))`

Total work done=
`1700+100`

Total work done=1800 J

Hence, work done is required to lift the barbell to a height of 2 m=1800 J