In-class quiz 13-1
A kilowatt-hour has the units of-A.
B.
C.
D.
E.
Power
Time
Energy
Force
Length
1 Kwh = 3.6x106 Joules
Lecture Quiz 13-2: Our Sun as a Pump
Period 5
A certain rain cloud at an altitude of 1.80 km contains
3.20x107 kg of water vapor. How long would it take in
hours for a 3.08-kW pump to raise the amount of water
from Earth's surface to the cloud's position?
A. 5.64x104
B. 6.16x104
C. 5.09x104
m
3 .2 x10 − 7 kg • 9. 8 2 • 1800 m
1hr
s
D. 4.93x104 ∆t = W = mg ∆y =
•
P
P
30800 w
3600 s
4
E. 6.63x10
Lecture Quiz 13-2: Our Sun as a Pump
Period 4
A certain rain cloud at an altitude of 2.10 km contains
3.20x107 kg of water vapor. How long would it take
in hours for a 2.97-kW pump to raise the amount of
water from Earth's surface to the cloud's position?
Neglect change in gravity with altitude.
A. 5.64x104
B. 6.16x104
m
−7
C. 5.09x104 ∆t = W = mg∆y = 3.2 x10 kg • 9.8 s 2 • 2100m • 1hr
P
P
29700w
3600s
D. 4.93x104
4
E. 6.63x10
Lecture Quiz 13-3
The reason we have not developed alternative
forms of energy in the last 50 years is:
A. Fossil fuels have been made artificially cheap
with government subsides
B. People have trouble planning for a bleak
future when there is plenty all around them
C. Both A and B
D. Neither A or B
E. What, me worry?
1