Question

A weightlifter lifts up a bar and weights of mass of 200 kg so that the bar is a height of

2.0 m above the ground. The radius of the largest disc on the bar is 20 cm. What is the gain
in PE when the weights are lifted?

Answer 1

The gain in potential energy when the weights are lifted is 3920 Joules.

Step-by-step explanation:

The gain in potential energy (PE) when the weightlifter lifts the bar and weights can be calculated using the formula PE = mgh, where m is the mass of the weights, g is the acceleration due to gravity (9.8 m/s²), and h is the height the bar is lifted.

In this case, the mass of the weights is 200 kg. The height the bar is lifted is 2.0 m. Plugging these values into the formula, we get PE = (200 kg)(9.8 m/s²)(2.0 m) = 3920 J.

Therefore, the gain in potential energy when the weights are lifted is 3920 Joules.

Answer 2

3924 Joules

Step-by-step explanation:

Potential Energy is calculated with the formula:

PE = mgh

From the problem m=200kg and h=2m so the gain in PE when the weights are lifted is 200*(9.81)*2 = 3924 J