The thermal efficiency of an engine is

where
W is the work done by the engine
Q is the heat absorbed by the engine to do the work
In this problem, the work done by the engine is W=200 J, while the heat exhausted is Q=600 J, so the efficiency of the machine is
Answer:
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Given :
A mover slides a refrigerator weighing 650 N at a constant velocity across the floor a distance of 8.1 m.
The force of friction between the refrigerator and the floor is 230 N.
To Find :
How much work has been performed by the mover on the refrigerator.
Solution :
Since, refrigerator is moving with constant velocity.
So, force applied by the mover is also 230 N ( equal to force of friction ).
Now, work done in order to move the refrigerator is :

Hence, this is the required solution.
Answer:
Bernoulli's equation states mathematically that if a fluid is flowing through a tube and the tube diameter decreases, then the velocity of the fluid increases, the pressure decreases, and the mass flow (and therefore volumetric flow) remains constant so long as the air density is constan
Explanation:
Answer:
Athlete A
Explanation:
Power is the rate of doing work and it is calculated as follows:
Power = work done/time taken = mgh/t
(for work being done against gravity)
So for athlete A
P = (100 kg * 9.8 N/kg* 0.6m)/0.5 s = 1176 W
For athlete B
P = (150 kg * 9.8 N/kg* 0.6m)/1 s = 882 W
For athlete C
P = (200 kg * 9.8 N/kg* 0.6m)/2 s = 588 W
For athlete D
P = (250 kg * 9.8 N/kg* 0.6m)/2.5 s = 588