An elevator does 81, 00 elevator J work to lift group of people 15 meters up to the 4th floor of a building. Determine the combined mass of the people in the elevator.

The combined mass of the people in the elevator is 55.1kg

Explanation:

Given-

Work done by the elevator, W = 8100J

Height, h = 15m

Combined mass of the people, m = ?

We know,

acceleration due to gravity, g = 9.8m/s²

Work done = potential energy of the elevator

W = mgh

8100J = m X 9.8 X 15

Therefore, combined mass of the people in the elevator is 55.1kg

answer: 2×10^-2kg

explanation: density= mass per volume

vol=mass/density

converting to s.i units we have;

3÷1000kg = 0.003

1.5÷100m = 0.15

0.003/0.15 = 0.02kg