Answer:
3.33, 4.84
Explanation:
A) Actual coefficient of performance can be calculated by the formula stated below
Actual COP = heat delivered/ work required
Actual COP = 2,000/600
Actual COP = 3.33
B) Th = High temperature = 80°C + 273 = 353K
Tl = Low temperature = 7°C + 273 = 280K
The theoretical maximum coefficient of performance can ve calculated by the formula
Theoretical COP = Th/(Th-Tl)
Theoretical COP = 353/(353-280)
Theoretical COP = 353/73
Theoretical COP = 4.84
Answer:
The magnitude of the force is 0.7255kN
Explanation:
The elevator floor acts on the person with a force that is due to the gravitational acceleration less the downward acceleration of the elevator:
(force of floor F) = (mass of person m) x [ (grav. acceleration g) - (elevator acceleration a) ]
in other words, considering the elevator floor as a reference frame in the Earth's gravitational field, the person's weight decreases due to the downward acceleration, as follows:

We are given the person's weight at rest, 0.9kN, from which the mass can be determined as:

So

I think the correct answer from the choices listed above is the second option. The <span> idea of plate tectonics was difficult for many scientists to accept for many years after it was first introduced because there </span><span>was no explanation yet for how it was happening. It was only to the recent times that these were proven. </span>
Speed, being a scalar quantity, is the rate at which an object covers distance. The average speed is the distance (a scalar quantity) per time ratio. ... Velocity is the rate at which the position changes. The average velocity is the displacement or position change (a vector quantity) per time ratio.
Answer:
675J
Explanation:
Given parameters:
Force = 45N
Distance = 15m
Unknown:
Work done by Sheila = ?
Solution:
Work done by a body is the amount of force applied to make a body move through a distance;
Work done = Force x distance
Now;
Work done = 45 x 15 = 675J