Answer:
The oven has many different heat sources from the bottom, sides, top, etc...
The microwave only has the sides.
Because: Some of the work done by the machine is used to overcome the friction created by the use of the machine. ... Work output can never be greater than work input. Machines allow force to be applied over a greater distance, which means that less force will be needed for the same amount of work.
Transform boundary
is the answer from stemscopes
Answer:
The minimum work per unit heat transfer will be 0.15.
Explanation:
We know the for a heat pump the coefficient of performance (
) is given by
where, 
is the magnitude of heat transfer between cyclic device and high-temperature medium at temperature 
and 
is the required input and is given by 
, 
being magnitude of heat transfer between cyclic device and low-temperature 
. Therefore, from above equation we can write,
Given, 
and 
. So, the minimum work per unit heat transfer is given by
Explanation:
Gas pedal is not required to used on friction less surface. On a friction less surface once the car is started and caused to move, car continues to move with same velocity as there is no opposing force. Therefore, no pressing of gas pedal required. However, this situation is not possible in real life, as friction is always present.
