Download Exam # 3 Fall 2009

Spring 2013
Final
Study Guide
Part I
Chapter 9
1.) The product of the average force and the time interval over which it acts is the
__________. (impulse)
2.) Ft = mv is the equation for __________. (impulse momentum)
3.) Under what conditions is momentum conserved? (in a closed, isolated system)
4.) An astronaut at rest fires a thruster pistol emitting xenon gas. Upon firing the astronaut
will ___________.(move in the opposite direction of the gas.)
7.) A 40.0 kg ice-skater glides with a speed of 2.0 m/s toward a 10.0 kg sled at rest on the
ice. The ice-skater reaches the sled and holds on to it. The ice-skater and sled then
continue on in the same direction in which the ice-skater was originally skating. What
is the speed of the ice skater after they collide? (1.6 m/s)
8.) What is the difference in momentum between a 50.0 kg runner moving at a speed of 3.00
m/s and a 3.00x103 kg truck moving at a speed of only 1.00 m/s? (2850 kg•m/s)
9.) A force of 16 N exerted against a rock with an impulse of 0.8 kg•m/s causes the rock to
fly off the ground with a speed of 4.0 m/s. What is the mass of the rock? (0.2 kg)
10.) A 6110 kg bus travelling at 20.0 m/s can be stopped in 24.0 s by gently applying the
brakes. What is the average force exerted on the bus? (5.09 x 103 N)
11.) A force of 200 N acts on a 7.0 kg bowling ball for 0.350 s. Calculate its change in
velocity. (10.0 m/s)
12.) The crumple zones around cars can reduce injury during a collision by _________.
(increasing the collision time thus reducing the force felt by the passengers in the car)
13.) A force of 16 N exerted against a rock with an impulse of 0.8 kg•m/s causes the rock to
fly off the ground with a speed of 4.0 m/s. What is the mass of the rock? (0.2 kg)
14.) In a collision momentum is conserved under which conditions? (in a closed, isolated system)
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Chapter 10-11
1.) How much work is done in pushing a tall box 15 m with a force of 4.0x102 N that is
applied slightly upward at an angle of 10.0o from the horizontal? (5900 J)
2.) The equation that represents gravitational potential energy is ___________. (PE = mgh)
3.) The equation for work is _________(W = F∆x)
4.) ________ is the rate of doing work. (power)
5.) A hydrolic lift raises a 1.14×103-kg car a distance of 2.4 m. If the car is lifted in 47 s,
how much power does the lift produce? (570 W)
6.) A student lifts a box of books that weighs 215 N. The box is lifted 1.75 m. What is the
change in energy of the box? (376 J)
7.) In which of the following case is work done: (Out of frustration the student kicks the
bucket.)
8.) Objects that are lifted against the force of gravity have stored energy known as
__________.(potential energy)
9.) A bike rider approaches a hill at a speed of 3.5 m/s. The mass of the bike and rider
together is 77 kg. What is the initial kinetic energy of the system? (4.7x102 J)
10.) In an inelastic collision momentum ___________? (only momentum is conserved)
11.) A large chunk of ice with mass 12.0 kg falls from a roof 6.00 m above the ground.
Ignoring air resistance, what is the speed of the ice when it reaches the ground? (10.8 m/s)
12.) Diego pulls a 4.5 kg sled across level snow with a force of 225 N on a rope that is 35.0o
above the horizontal. If the sled moves a distance of 65.3 m, how much work does Diego do?
(1.20x104 J)
13.) The energy of an object resulting from its motion is __________ energy. (kinetic)
14.) The equation for the kinetic energy of an object is _________. (KE = ½ mv2)
15.) If you exert a force on an object in the direction opposite to its motion, the kinetic
energy of the object ________(decreases)
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16.) A 16.8-kg boy is riding in a 4.50-kg wagon. A 14.0-kg girl pushes the wagon and exerts
a constant force of 2.60 N over a distance of 3.50 m. What is the change in energy of
the boy and the wagon? (9.10 J)
17.) An elevator lifts a total mass of 1.1x103 kg a distance of 40.0 m in 12.5 s. How much
power does the elevator generate? (3.4x104 W)
18.) A student lifts a box of books that weighs 215 N. The box is lifted 1.75 m. What is the
change in energy of the box? (376 J)
19.) In which of the following case is work done: (A student pushes a book across her desk.)
20.) The sum of the kinetic and gravitational potential energies of a system is called
__________. (conserved energy)
21.) In an elastic collision momentum ___________? (momentum and kinetic energy are
conserved)
Chapter 12
1.) You have equal masses of four of the substances listed in Table 12-1. All are at the same
initial temperature, and then you place them in a hotter room. Which of the objects'
temperatures will increase the most rapidly? (Lead)
3.) When disorder increases, entropy _________. (increases)
4.) If the final temperature of a system is greater than the initial temperature, ∆t is
__________. (positive)
5.) __________ is the amount of energy that must be added to a material to raise one unit of
mass by one temperature unit? (Specific heat)
6.) Heat spontaneously flowing from a cold body to a hot body violates the __________.
(second law of thermodynamics)
7.) Which of the following temperature conversions is incorrect? (298 K = 571o C)
8.) What are the units of specific heat: (J/kg • K)
9.) Which of the following statements about thermal equilibrium is false?
(Thermal equilibrium is used to create energy in a heat engine.)
10.) What is the change in temperature of 2.2 kg of ice if 8.5 x 103 J of thermal energy is added to it?
(1.9 K)
11.) An increase in heat in a system __________. (increases entropy)
12.) How much heat is needed to warm 363 mL of water in a baby bottle from 24o C to
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38o C? (density water = 1kg/L) (21 kJ)
13.) Which is an example of a heat engine? (locomotive engine)
14.) Friction that you feel when you rub your hands together was changed from __________
to heat. (kinetic energy)
15.) The thermal energy needed to boil a liquid is the heat of __________. (vaporization)
16.) A 2.00 x 103-g sample of water at 100o C is mixed with a 4.00 x 103-g sample of water at
0.0o C in a calorimeter. What is the equilibrium temperature of the mixture? (33o C)
17.) A 1500 kg automobile comes to a stop from 25 m/s. All of the energy of the automobile is
deposited in the brakes. Assuming that the brakes are about 45 kg aluminum, what would be the
change in temperature of the brakes? (12o C)
18.) Which of the following statements about thermal equilibrium is false?
(Thermal equilibrium is used to create energy in a heat engine.)
19.) Friction that you feel when you rub your hands together was changed from __________
to heat. (kinetic energy)
20.) The average kinetic energy of ice particles__________ as ice melts. (remains constant)
21.) What does a calorimeter measure? (change in thermal energy)
22.) Heat is transferred by __________ when objects touch. (Conduction)
23.) If the final temperature of a system is less than the initial temperature, ∆t is
__________. (negative)
24.) If the final temperature of a system is less than the initial temperature, ∆t is
__________. (negative)
25.) What is the change in temperature of 2.2 kg of steam if 8.5 x 103 J of thermal energy is added to
it ___________?(1.9 K)
26.) How much heat is absorbed from the surroundings when 81 g of 0.0o C ice in a beaker
melts and warms to 10o C? (30 kJ)
27.) In which direction does heat flow? (from hot to cold)
28.) The Sun warms us by __________. (radiation)
Chapter 13
1.) A car tire makes contact with the ground on a rectangular area of 12 cm by 18 cm. If the
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car’s mass is 925 kg, what pressure does the car exert on the ground as it rests on all four
tires? (100 kPa)
2.) Dentists’ chairs are examples of hydraulic-lift systems. If a chair weighs 1600 N and rests on a
piston with a cross-sectional area of 1440 cm2, what force must be applied to the smaller piston, with
a cross-sectional area of 72 cm2, to lift the chair? (80 N)
3.) Common brick is about 1.8 times denser than water. What is the apparent weight of a 0.20 m3
block of bricks under water? (1600 N)
4.) A piece of steel is 11.5 cm long at 22o C. It is heated to 1221o C, close to its melting temperature.
How long is it? (12 cm)
5.) A 0.85 kg physics textbook with dimensions 24.0 cm x 20.0 cm is at rest on a table. What pressure
does the book apply? (170 Pa)
6.) A lead brick, 5.0 cm x 10.0 cm x 20.0 cm, rests on the ground on its smallest face. Lead
has a density of 11.8 g/cm3. What pressure does the brick exert on the ground? (23 kPa)
7.) A mechanic exerts a force of 55 N on a 0.015 m2 hydraulic piston to lift a small automobile. The
piston that the automobile sits on has an area of 2.4 m2. What is the weight of the automobile?
(8080 N)
8.) What is the tension in a wire supporting a 1250 N camera submerged in water? The volume of the
camera is 16.5x10-3 m3. (1090 N )
9.) A tank truck takes on a load of 45,725 L of gasoline in Houston, where the temperature is 28.0o C.
The truck delivers its load in Minneapolis, where the temperature is -12.0o C. How many liters of
gasoline does the truck deliver? (4.4x104 L)
Chapter 14 – 15
1.) The speed of a wave depends on the __________. (medium)
2.) When a continuous wave meets a boundary that transmits the wave at a lower speed, the
wavelength __________. (decreases)
3.) What mathematical expression relates frequency to period? (f = 1/T)
4.) If a wave's frequency increases, its period __________. (decreases)
5.) A pulse traveling along a bullwhip is an example of a __________ wave: (transverse)
6.) What does a wave carry? (energy)
7.) What produces the human voice? (vibrations in vocal chords)
8.) What is the logarithmic scale that measures sound level? (decibel)
9.) What is a sound wave? (a pressure variation transmitted through matter)
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10.) Sound cannot travel through _________. (a vacuum)
11.) The sound from a string instrument, like a guitar, results from __________. (vibrating
strings)
12.) What is the force acting on a spring with a spring constant of 275 N/m that is stretched
14.3 cm? (39.3 N)
13.) What is the frequency of a wave with a period of 3 s? (0.3 Hz)
14.) What mathematical expression relates frequency to period? (f = 1/T)
15.) When a wave pulse strikes a wall, it reflects back and is __________. (inverted)
16.) Paulo is listening to classical music in the speakers installed in his swimming pool. A note with a
frequency of 327 Hz reaches his ears while he is underwater. What is the wavelength of the
sound that reaches Paulo’s ears? Use 1493 m/s for the speed of sound in water. (4.57 m)
17.) A clock pendulum has a period of 0.95 s. How much longer will it have to be to have a period of
1.0 s? (2.4 cm longer)
18.) The engine on a motorcycle hums at 85 Hz. If the motorcycle travels toward a resting
observer at a velocity of 29.6 m/s, what frequency does the observer hear? Use 343 m/s for
the speed of sound. (93 Hz)
19.) A trough is __________ of a wave. (the low point)
20.) What is the period of a 3.5 m-long pendulum on Earth? (3.8 s)
21.) When a wave pulse strikes a wall, it reflects back and is __________. (inverted)
22.) A wave with a frequency of 10 Hz and a wavelength of 2 m has a speed of __________.
(20 m/s)
23.) Surface waves move in a position __________ to the direction of the wave motion.
(both parallel and perpendicular)
24.) During the Doppler shift, approaching sound waves __________?(shorten)
25.) Sound waves, like other waves, __________. (reflect off a hard surface)
26.) Long-term exposure to loud sounds can __________. (decrease high-frequency hearing)
27.) What is the logarithmic scale that measures sound level? (decibel)
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28.) What is the value of the spring constant of a spring with a potential energy of 8.67 J
when it is stretched 247 mm. (284 N/m)
29.) A spring with a spring constant of 350 N/m pulls a door closed. How much work is done
as the spring pulls the door at a constant velocity from 85.0 cm to a 5.0 cm stretch? (130 J
30.) The length (L) of a closed-pipe resonator is __________. (1/4 wavelength or odd
multiple threrof)
31.) The speed of a wave depends on the __________. (medium)
32.) What mathematical expression relates frequency to period? (f = 1/T)
33.) What does a wave carry? (energy)
34.) What is the length of a pendulum that has a period of 4.89 s? (5.94 m)
35.) The sound from a trumpet travels at 351 m/s in air. If the frequency of the note is 298 Hz, what is
the wavelength of the sound wave? (1.18 m)
36.) The horn of a car attracts the attention of a stationary observer. If the car is approaching the
observer at 60.0 km/h and the horn has a frequency of 512 Hz, what is the frequency of the
sound perceived by the observer? Use 343 m/s for the speed of sound in air. (538 Hz)
37.) How many centimeters will a spring stretch when a 2.6 kg block is hung vertically from a spring
with a spring constant of 89 N/m? (25 cm)
38.) How much elastic potential energy does a spring with a constant of 54 N/m have when it is
stretched 18 cm? (0.87 J)
39.) What is the length of a pendulum with a period of 89.4 ms? (1.98x10-3 m)
Chapter 16
1.) Light behaves as __________. (a particle and a wave)
2.) A medium that allows light to pass through but does now allow the light source to be
visible is__________. (translucent)
3.) A ray of light travels in a _________. (straight line)
4.) How do the frequencies of red and violet light compare? (violet is higher)
Chapter 17
1.) Real images produced by mirrors have __________ magnification. (negative)
2.) __________ is located behind a convex mirror. (the focal point)
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3.) The distance from the focal point to the mirror is the __________. (focal length)
4.) When an object is placed between the focal point and a concave mirror, the rays
__________. (diverge and sight lines converge and form a virtual image)
5.) A __________ image is formed when light rays converge and pass through the image.
(real)
6.) Your image in a bathroom mirror results from __________. (specular reflection)
7.) What does the F on a ray diagram represent? (the focal point)
8.) A 10-cm object has a 20-cm image. What is the magnification? (2)
9.) The image from a convex mirror will _________. (always be virtual)
10.) Where is the object located if the image that is produced by a concave mirror is smaller
than the object? (past the center of curvature)
11.) What is the focal length of a concave mirror that magnifies, by a factor of +3.2, an object
that is placed 30 cm from the mirror? (44 cm)
12.) An object is placed 21 cm in front of a concave mirror with a focal length of 14 cm.
What is the image position?(42 cm)
14.) A ray of light strikes a plane mirror at an angle of 23o to the normal. What is the angle
between the reflected ray and the mirror? (67o)
15.) A concave mirror produces an inverted image that is 8.5 cm tall, located 34.5 cm in front
of the mirror. If the focal point of the mirror is 24.0 cm, then what is the height of the
object that is reflected? (19 cm)
16.) A concave mirror with a focal length of 16.0 cm produces an image located 38.6 cm
from the mirror. What is the distance of the object from the front of the mirror?(27.3 cm)
17.) A convex mirror is used to produce an image that is three-fourths the size of an object
and located 8.4 cm behind the mirror. What is the focal length of the mirror? (-34 cm)
Chapter 18
1.) Water is more optically dense than air. Therefore, the speed of light in water is
__________. (slower than the speed of light in air)
2.) According to Snell's law, light traveling from a vacuum to glass will __________. (slow
down)
3.) The refractive indices of lenses are __________. (greater than air)
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4.) A ray of sunlight travels through air and intersects the surface of water at a small incident
angle. The ray is __________. (refracted)
5.) An image of a flower is seen through a lens. What is the object? (a flower)
6.) What does Snell's law compare? (the sines of the refracted angles)
7.) The focal length of a concave lens is ________. (negative)
8.) Unlike mirrors, lenses have _______. (two focal points)
9.) A light ray is traveling through an unknown material when it intersects ethanol (n = 1.36)
at an incident angle of 62.0°. If the angle of refraction is 46.4°, what is the index of
refraction of the unknown material? (1.12)
10.) A flashlight beam is directed at a swimming pool in the dark at an angle of 46o with
respect to the normal to the surface of the water. What is the angle of refraction of the
beam in the water? (The refractive index for water is 1.33). (33o)
11.) The speed of light in diamond is 1.24x108 m/s. What is the index of refraction of
diamond? (2.42)
12.) What is the magnification of an object that is 4.15 m in front of a camera that has an
image position of 5.0 cm? (-0.012)
13.) What is the critical angle for total internal reflection when light travels from glass
(n=1.52) to water (n=1.33)?(61.0o)
14.) What is dispersion? (the separation of light into its spectrum)
15.) A beam of light strikes the flat, glass side of a water-filled aquarium at an angle of 40.0o
to the normal. For glass, n=1.50. At what angle does the beam enter the glass? (25.4o)
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