Answer:
efficiancy=40 percent
Explanation:
efficiency=energy output/energy input×100
efficiancy=8J/20J×100
efficiancy=0.4×100
efficiancy=40 percent
Mark brianliest if my answer suit your question..
The energy achieved I think
Hi there!
The period of an orbit can be found by:

T = Period (? s)
r = radius of orbit (6400000 m)
v = speed of the satellite (8000 m/s)
This is the same as the distance = vt equation. The total distance traveled by the satellite is the circumference of its circular orbit.
Let's plug in what we know and solve.

Newton's third law of motion
Explanation:
Newton's third law of motion states that:
<em>"When an object A exerts a force on an object B (action force), then object B exerts an equal and opposite force (reaction force) on object A"</em>
It is important to note that this law is always valid, even when it seems it is not.
Consider for example the gravitational force that the Earth exerts on your body (= your weight). We can say that this is the action force. It may seems that there is no reaction force in this case. However, this is not true: in fact, your body also exerts an equal and opposite force on the Earth, and this is the reaction force. The reason that explains why we don't notice any effect on Earth due to this force is that the mass of the Earth is much larger than your mass, therefore the acceleration produced on the Earth because of the force you apply is negligible.
It is also important to note that the action-reaction pair of forces always act on two different objects, so they never appear in the same free-body diagram.
Learn more about Newton's third law of motion:
brainly.com/question/11411375
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