Answer:
56.86153 N
Explanation:
t =Time taken
F = Force
Power

Work done

The magnitude of the force that is exerted on the handle is 56.86153 N
C. element only one substance
Answer:
Work done to pull the piano upwards is 401250 J
Explanation:
Work is done against the gravity to pull the piano upwards
So here we can say that work done is

here we know that

also we know that
H = 75 m
now we have


Answer:
The answer is not able to be solved, because we dont know what objects are in it, and how heavy they are. More information please!
Explanation:
We could use the change of pressure to calculate for the height climbed by the mountain hiker. The change of pressure is given by
p = rho * g * h, where p is the change of pressure, rho is the air density, g is the acceleration due to gravity, and h is the height.
Using the conversion 1 mbar = 100 Pa,
(930 - 780)(100) = (1.20)(9.80)h
15000 = 1.20*9.80*h
h = 1.28 km