It has changed because earlier in the days people couldn't even figure out if the world was flat or round but now we can add decimals and multiply fractions.
-the contact force
-weight of an object
-the surfaces in contact (coefficient of friction).
these are what I think are the answer
Answer:
Explanation:
A)
W = work done by the freezer = 800 J
Q = heat removed from the freezer = 1735 J
Q' = Heat expelled into the room
Coefficient of performance is given as

inserting the values


B)
Heat expelled is given as
Q' = W + Q
Q' = 800 + 1735
Q' = 2535 J
The acceleration due to gravity is not due to the Earth's motion through space. It is due to the gravitational force pulling you towards the center of mass of the Earth. The ground pushes back<span>, and what you </span>feel<span> is </span>your<span> weight. This is the same as what you </span>feel<span> in an accelerating </span>car<span>.</span>