Answer:
800 Watts
Explanation:
Power = Work/time
Working in SI units, Power = Watts, Work = Joules, Time = seconds.
Power = 2240J/2.8s = 800 Watts.
Answer:
The first is the closest in absolute values.
The second two are vague and the last is approximate.
Answer:
The efficiency is 0.33, or 33%.
Explanation:
From the thermodynamics equations, we know that the formula for the efficiency of a heat engine is:

Where η is the efficiency of the engine, Q_1 is the heat energy taken from the hot source and Q_2 is the heat energy given to the cold object. So, plugging the given values in the formula, we obtain:

This means that the efficiency of the heat engine is 0.33, or 33% (The efficiency of an engine is dimensionless).
Answer:
5500000 millimeters
Explanation:
1 kilometre= 1000 meter
5.5 km=5.5 * 1000
=5500
Now,
1 metre = 1000 millimetres
5500 metre=1000*5500
=5500000 mm