Answer:
(a) W = 1329.5 J = 1.33 KJ
(b) ΔU = 24.27 KJ
Explanation:
(a)
Work done by the gas can be found by the following formula:

where,
W = Work = ?
P = constant pressure = (0.991 atm)(
) = 100413 Pa
ΔV = Change in Volume = 18.7 L - 5.46 L = (13.24 L)(
) = 0.01324 m³
Therefore,
W = (100413 Pa)(0.01324 m³)
<u>W = 1329.5 J = 1.33 KJ</u>
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(b)
Using the first law of thermodynamics:
ΔU = ΔQ - W (negative W for the work done by the system)
where,
ΔU = change in internal energy of the gas = ?
ΔQ = heat added to the system = 25.6 KJ
Therefore,
ΔU = 25.6 KJ - 1.33 KJ
<u>ΔU = 24.27 KJ</u>
C.
The particles move perpendicular to the direction of the wave.
Explanation:
Gravitational potential energy = mgh = (5)(9.81)(7) = 343.35J.
The gravitational field is the Force divided by the mass
Call g the gravitational fiel, F the force exerted by the earth and m the mass of the telescope.
g = F / m
g=9.1x10^4 N / 1.1 x 10^4 kg = 8.27 N/kg
Note that the unit N/kg is equivalent to m/s^2