Question

In which of the following cases is there no work done?
a. A weightlifter lifts a barbell
b. A weightlifter holds a barbell overhead
c. A weightlifter slowly lowers a barbell
d. A werghtlifter drops a barbell and falls to the ground​

Answer 1

Answer:

In which of the following cases is there no work done?

a. A weightlifter lifts a barbell

b. A weightlifter holds a barbell overhead

c. A weightlifter slowly lowers a barbell

d. A werghtlifter drops a barbell and falls to the ground

Explanation:

ans is A werghtlifter drops a barbell and falls to the ground

Answer 2

Answer:

Ur answer....❤

Explanation:

In options

(a) and

(c), no work is done because the force of gravity in option a. and the centripetal force in option c. are perpendicular to the direction of displacement. In option

(b), no net force acts on the raindrop since it is falling with a uniform velocity, hence no work is done.