Which one is correct? As weightlifter lifts a barbell with his hands: A. the bar
ID: 2290424 • Letter: W
Question
Which one is correct?
As weightlifter lifts a barbell with his hands:
A. the barbell does positive work on the weightlifter's hands and the weightlifter's hands do negative work on the barbell. B. the barbell does negative work on the weightlifter's hands and the weightlifter's hands do positive work on the barbell. C. the barbell does negative work on the weightlifter's hands and the weightlifter's hands do negative work on the barbell. D. the barbell does positive work on the weightlifter's hands and the weightlifter's hands do positive work on the barbell.Explanation / Answer
Barbell applies a force equal to its weight on the lifter, but
Net force applied by lifter on the barbell is more than the weight, otherwise it can not be lifted.
so answer is D