### 28 April 2000 Test   Name:

Mechanics Keys
d = 0.5 g t2
Fg = (G m1 m2 )/r2
g = (4 p² L)/t2
P = F/A
r = m/V
v = d/t
W = F·d (dot product)
T = F × d (cross product)
A = Area
a = coeficient of linear friction
c = specific heat capacity
D = change in
d = distance
F = Force
Fe= Electrical force
Fg = Force of gravitational attraction
f = frequency
g = acceleration of gravity
G = 6.67 x 10-11
i = current
L = Length
Li = initial length
Lf = final length
DL = change in length ( Lf - Li )
l = waveLength
m = mass
P = power
P = Pressure
r = density
p = 3.1415926535897932384626433832795...
q = charge
Q = Energy or Work ( usually in calories)
R = Resistance
t = time
Tf = final Temperature
Ti = initial Temperature
DT = change in Temperature (Tf - Ti)
T = Torque
t = period
v = velocity
V = Voltage
V = Volume
W = Energy or Work (usually Joules)
Heat
Q = m c DT
DL = a Li DT
DT = Tf - Ti
Waves and Sound
v = f l
f = 1/t
Electricity
Fe = [(9×109) q1 q2 ]/r2
i = q/t
P = i V
V = i R
P = i2 R
1. A block is pushed 10 meters along the floor with a force of 7 Newtons in the direction of motion of the block.
1. Was work done?

2. If work was done, how much work was done? If work was not done, what happened to the force?

2. Heat can move by convection.  What is convection?

3. Heat can move by radiation.  Give an example of heat radiation.

4. Heat can move by conduction.  Give an example of heat moving by conduction.

5. Which stores more heat per kilogram, lead (cPb = 0.031 cal/g°C) or copper ( cCu = 0.092 cal /g°C)?

6. 4.0 m of copper pipe is heated from 30°C to 100°C.  If the coeficient of linear expansion a for copper is 17 × 10-6/°C, what is the change in length DL for the pipe?

7. A 600 gram piece of metal loses 1300 calories cooling from 100°C to 30°C.  What is the specific heat capacity of the metal?

8. The speed of sound is given by the formula:
speed of sound = 331 m/s + 0.610 × T
What is the speed of sound at 28°C?

9. A piece of equipment called a Phlogiston 9000 has a warning label on it that says, "Caution!  This Phlogiston produces 140 decibels."  What safety precaution should you take before you turn it on?

10. A water wave with a crest to crest distance of 30 meters has a time between crests of 15 seconds. What is the speed of the wave?

11. Two wave crests are separated by 15 meters.  What is the wavelength l of the wave in meters?

12. A person is yelling from a woman's dorm window.  If the speed of sound is 350 m/s and the distance from the dorm to the cafeteria is 70 meters, how long does it take the sound to reach the cafeteria?

13. You are standing outside watching an approaching storm.  You hear thunder 15 seconds after seeing a lightning flash.  You do not have your calculator with you.   To the nearest kilometer, how far away was the lightning strike?

14. A cliff is located 131 meters away from me.  If the temperature is 28°C and the speed of sound at 28°C is 348 m/s, how long in seconds until I hear the echo?

15. In one of the classes I rubbed a piece of plastic with a wool cloth. I then brought the piece of plastic near small bits of paper and attracted the paper.  I also brought the rod near someone's head and attracted their hair to the rod.  This experiment worked better in one section than the other, but aside from experimental difficulties, what caused the paper and hair to be attracted to the rod?

16. If a positive charge of 5 coulombs is located 0.3 meters from a negative charge of 5 coulombs, will the charges attract or repel each other?

17. If a positive charge of 5 coulombs is located 0.3 meters from a negative charge of 5 coulombs, what is the force between the charges?

18. Which of the following circuits will light up?  Circle the correct answer.
a.b.c.

19. Circle the series circuit below.
a.b.

20. A charge of 36,000 Coulombs flows through a wire for one hour.  How many Amperes of electricity flowed through the wire during that one hour?

21. A Panasonic 10 cup Rice-O-Mat model SR-W18FXP rice cooker consumes 600 Watts of power at 120 Volts.  How many Amperes of current does the SR-W18FXP rice cooker consume?

22. What is the resistance in ohms of the SR-W18FXP rice cooker?

23. An Ace Hardware PT-BF04 Transient Surge Suppressor Power Strip is rated to handle a maximum of 15 Amperes. How many SR-W18FXP rice cookers can be safely plugged into this power strip?

24. Is copper a conductor?

25. Is paper a conductor?

26. Can magnetic forces travel through a wood table top?

27. List the seven colors of the rainbow:

1. ____________________

2. ____________________

3. ____________________

4. ____________________

5. ____________________

6. ____________________

7. ____________________