This can be seen as a trick question because heat engines can typically never be 100 percent efficient. This is due to the presence of inefficiencies such as friction and heat loss to the environment. Even the best heat engines can only go up to around 50% efficiency.
False , the gas petal makes the speed go up
Answer:
106.24 kJ.
Explanation:
Given that,
Mass of sample of sand, m = 8 kg
Specific heat of sand, c = 664 J/kg-°C
The temperature changes from 20° C to 40° C. We need to find the change in thermal energy. It is given by :

So, the change in thermal energy is 106.24 kJ.