B) The heat absorbed by the engine is
while the heat expelled is
, therefore the work done by the engine is the difference between the heat absorbed and the heat expelled:
a) The efficiency of the engine is the ratio between the work done by the engine and the heat absorbed, therefore:
Answer:
The work done by Joel is greater than the work done by Jerry.
Explanation:
Let suppose that forces are parallel or antiparallel to the direction of motion. Given that Joel and Jerry exert constant forces on the object, the definition of work can be simplified as:
Where:
- Work, measured in joules.
- Force exerted on the object, measured in newtons.
- Travelled distance by the object, measured in meters.
During the first 10 minutes, the net work exerted on the object is zero. That is:
In exchange, the net work in the next 5 minutes is the work done by Joel on the object:
Hence, the work done by Joel is greater than the work done by Jerry.
First, you need forces attracting the Sun and Earth toward each other. That's described by Newton's law of universal gravitation.
Then you need the description of how that force causes the planet to move in a circular path. The best choice is Newton's <em>Second law</em> of motion: F = m A .
Oh my gosh had the same question
