Answer:
2000 kg/m³
Explanation:
Density = (mass[kg])/(volume[m³])
Density of the brick = (.128kg)/(.02•.04•.08) = 2000 kg/m³
Answer:
Explanation:
Work done by the person depends on its mass and the height raised. It also depends on the acceleration due to gravity.
As the height raised and the mass of person is same. The value of acceleration due to gravity is also constant So, the work done is also same in both the cases.
Answer:
0.237 (23.7 %)
Explanation:
The thermal efficiency of an engine is given by:

where
W is the useful work output of the engine
is the heat in input
Here we have:

and the work done is the total heat in input minus the heat exhausted:

So, the efficiency is
(23.7 %)