Answer:
gravitational potential energy:
GPE = m g h
kinetic energy:
KE = 1/2 m v^2
1) 72/4 = 18 years
2) 72/10 = 7.2 years
3) 72/13 = 5.54 years
Explanation: With the rule of 72, you simply take 72 and divide it by whatever the rate of return (or return on investment) is.
Let me know if you have any questions.
Answer:
(a). 14.4 lbf/in^2.
(b). 27.8 in, AS THE TEMPERATURE INCREASES, THE LENGTH OF MERCURY DECREASES.
Explanation:
So, from the question above we are given the following parameters which are going to help us in solving this particular Question;
=> The "barometer accidentally contains 6.5 inches of water on top of the mercury column (so there is also water vapor instead of a vacuum at the top of the barometer)"
=> "On a day when the temperature is 70oF, the mercury column height is 28.35 inches (corrected for thermal expansion)."
With these knowledge, let us delve right into the solution;
(a). The barometric pressure = water vapor pressure + acceleration due to gravity (ft/s^2) × water density(slug/ft^3) × {ft/12 in}^3 × [ height of mercury column + specific gravity of mercury × height of water column].
The barometric pressure= 0.363 + {(62.146) ÷ (12^3) × 390.6425}. = 14.4 lbf/in^2.
(b). { (13.55 × length of mercury) + 6.5 } × (62.15÷ 12^3) = 14.4 - 0.603.
Length of mercury = 27.8 in.
AS THE TEMPERATURE INCREASES, THE LENGTH OF MERCURY DECREASES.
<u><em>Answer:</em></u>
The answer is 1400 J, according to my Physics teacher.
<u><em>Explanation:</em></u>
You need to take into account everything that is listed in the question; it's important to remember that the question is asking about the change in gravitational potential energy of the object-object-Earth system from 0s to 10s, not 0s to 20s. :)
The input work = Force x distance
So I/P = 45 x 1.5 = 67.5 N.m
The output work = Force x distance
So, O/P = 87.6 x 0.4 = 35.04 N.m
Efficiency = (output work / Inputwork) x 100
= ( 35.04/67.5) x100
Efficiency = 51.91 %
