Xiao Li, who weighs 400N, used a bucket with a weight of 10N to lift up the water with a weight of10n, and sent it to the dormitory with a height of 6 meters along the stairs for use. This time, she lifted the water.
Carrying a bucket upstairs, what does it do to water?
W useful =G water h= 100N×6m=600J,
Additional work completed:
W quantity =G person h+G bucket h = 400 n× 6 m+10 n× 6 m = 2460 j.
Therefore, choose: B.