-- The potential energy of a 12-lb bowling ball up on the shelf
doesn't have anything to do with the temperature of the ball or
the shelf.
-- The potential energy of a jar full of gas does depend on the
temperature of the gas. The warmer it is, the greater its pressure
is, and the more work it can do if you let it out through a little hole
in the jar. If it gets hot enough, it'll have enough potential energy
to blow the jar to smithereens.
If the absolute pressure of a gas is 550.280 kPa, its gage pressure is
<span>
a. 101.325 kPa.
b. 448.955 kPa.
c. 651.605 kPa.
d. 277.280 kPa.</span>
The answer is B.
Hi there!
(a)
Recall that:

W = Work (J)
F = Force (N)
d = Displacement (m)
Since this is a dot product, we only use the component of force that is IN the direction of the displacement. We can use the horizontal component of the given force to solve for the work.

To the nearest multiple of ten:

(b)
The object is not being displaced vertically. Since the displacement (horizontal) is perpendicular to the force of gravity (vertical), cos(90°) = 0, and there is NO work done by gravity.
Thus:

(c)
Similarly, the normal force is perpendicular to the displacement, so:

(d)
Recall that the force of kinetic friction is given by:

Since the force of friction resists the applied force (assigned the positive direction), the work due to friction is NEGATIVE because energy is being LOST. Thus:

In multiples of ten:

(e)
Simply add up the above values of work to find the net work.

Nearest multiple of ten:

(f)
Similarly, we can use a summation of forces in the HORIZONTAL direction. (cosine of the applied force)



Nearest multiple of ten:

A single polarizer will stop 50% of the incoming light.
The wise and careful use of energy is called CONSERVATION