Physics final

How many joules of heat energy are needed to raise the temperature of 10 g of aluminum from 22°C to 55°C, if the specific heat of aluminum is 0.90 J/g°C? Using this formula: Q = m c (Δ T)

297

A horizontal force of 5.0 Newtons acts on a 3.0-kilogram mass over a distance of 6.0 meters along a horizontal, frictionless surface. What is the change in kinetic energy of the mass during its movement over the 6.0-meter distance?

30

How much work is performed when a 50 kg crate is pushed 15 m with a force of 20 N?

300J

How much heat energy must be absorbed by 20 g of water to increase its temperature from 283 °C to 303 °C? (specific heat of H2O = 4.184 J/g °C) Using this formula: Q = m c (Δ T)

1673.6

How much heat energy is given out when 85 g of lead cools from 200 °C to 10 °C? (specific heat of lead = 0.129 J/g °C) Using this formula: Q = m c (Δ T)

2083.35

The magnitude of the gravitational force between a planet and a satellite is F. If the distance between the planet and satellite is doubled, the gravitational force between them will become A F/4 B 2F C F/2 D 4F

A F/4

When a planet and a satellite are a distance d apart, the magnitude of the gravitational force between them is F. If the distance between them is increased to 3d, the magnitude of the gravitational force between them will be A F/9 B F/3 C 2F D 4F

A F/9

A student touches a metal sink with her finger and notices that her finger feels cold. Which of the following statements explains this observation? A Heat energy flows from the student's finger to the metal sink. B Heat energy flows from the metal sink to the student's finger. C The student's finger was originally at the same temperature as the sink. D The student's finger was originally at a lower temperature than the sink.

A Heat energy flows from the student's finger to the metal sink.

A F1 race car emits a certain pitch, which is heard by a observers. In which of the following situations would the observer perceive the highest frequency of sound? A The observer and race car are both stationary, B The observer walks at 5 m/s toward the stationary race car. C The observer is stationary while the race car drives toward the observer at 200 mph. D The observer is stationary while the race car drives away from the observer at 200 mph

C The observer is stationary while the race car drives toward the observer at 200 mph.

An unknown material absorbs 1800J of energy and its temperature changed 55°C. If there was 80g of the material, what was the specific heat of the material? Using this formula: Q = m c (Δ T)

.41

A man applies a force of 100 N to a rock for 60 seconds, but the rock does not move. What is the amount of work done by the man on the rock?

0

A person is using a force of 200 N to push a box. How much power does the person need to push the box a distance of 4 m in 10 s? P = W / t

80

The magnitude of the electrostatic force between two point charges is F. If the distance between the charges is doubled, the electrostatic force between the charges will become A F/4 B 2F C F/2 D 4F

A F/4

The spreading of a sound wave around a corner, through an opening, or into the region behind an obstruction is called A diffraction B absorption C reflection D refraction

A diffraction

In trial 1, students measure the period of a mass on a spring oscillating up and down. In trial 2, students increase only the mass of the mass-spring system and then again, measure the period. The period of the mass in trial 2 will A Increase B Decrease C Remain the same D None of the Above

A Increase

When an uncharged balloon is rubbed against dry uncharged hair, electrons move from the hair onto the balloon's surface. Which table lists the charges of the balloon and the hair after they are moved apart?

balloon is negative Hair is positive

what component converts chemical energy into electrical energy

battery

liquid water-4.18 solid water (ice)-2.11 water vapor-2 dry air- 1.01 basalt-.84 granite- .79 iron-.45 copper-.38 lead-.13 Of these: dry air, water vapor, ice and liquid water -- which of them will cool off faster after being heated?

dry air

When a DVD is read, laser light touches the DVD surface and is then measured at location A. What allows light to return to location A after striking the DVD surface A Conduction B Refraction C Magnification D Reflection

D Reflection

A solid object at 30⁰C is placed inside a container of liquid at 60⁰C. What most likely will be observed? A The temperature of the liquid will remain the same. B The temperature of the solid decrease C The temperature of the liquid will increase D The temperature of the solid will increase

D The temperature of the solid will increase

A clothes iron is designed to be used with a 220 V outlet. Which of the following will happen if the iron is plugged into a 110 V outlet instead of a 220 V outlet? A The iron will exceed its maximum power rating. B The internal resistance of the iron will increase C The iron will use the same energy for a given amount of time. D The current delivered to the iron will be lower than the maximum amount

D The current delivered to the iron will be lower than the maximum amount

Based on Ohm's law, which of the following statements explains what must happen when the voltage across a resistor is decreased A The resistance of the resistor increases. B The resistance of the resistor decreases. C The current through the resistor increases. D The current through the resistor decreases.

D The current through the resistor decreases.

Two positively charged masses are separated by a distance, r. Which statement best describes the gravitational and electrostatic forces between the two masses? A Both forces are attractive. B Both forces are repulsive. C The gravitational force is repulsive and the electrostatic force is attractive. D The gravitational force is attractive and the electrostatic force is repulsive.

D The gravitational force is attractive and the electrostatic force is repulsive.

While playing a game at a fair, a person lifts a mallet above her head. The diagram below shows the mallet at its highest point. She then uses the mallet to strike the target on the ground. The kinetic energy of the mallet once it hits the target is greater than the potential energy of the mallet at its highest point. Which of the following statements best explains why this fact does not violate the law of conservation of energy. A Gravity is constant as she swings the mallet. B There is more air resistance near the target. C Acceleration due to gravity is greater at the target. D Work tranfsormed into Kinetic Energy is added by the woman to the mallet.

D Work tranfsormed into Kinetic Energy is added by the woman to the mallet.

In which of the following examples is heat transferred primarily by radiation A A fan blows warm air around a room B A hot water bottle warms a person's feet. C Water vapor from a shower warms the room D Your hand placed closely near the side of a light bulb that has been turned on.

D Your hand placed closely near the side of a light bulb that has been turned on.

The diagram below shows a bar magnet within a coil of conducting wire. The magnet is moved back and forth. The magnet never has contact with the wire. As the magnet is moved, the wire will A decrease in temperature. B become negatively charged. C demagnetize the bar magnet. D have an electric current.

D have an electric current.

In a generator the uses magnets to produce electricity, what effect does an increase in the magnetic field strength within the generator produce? A lower resistance B lower current C lower voltage D higher voltage

D higher voltage

The work done in accelerating an object along a frictionless horizontal surface is equal to the change in the object's A momentum. B potential energy. C velocity. D kinetic energy.

D kinetic energy.

If the distance separating a planet and an orbiting satellite is halved, the magnitude of the gravitational force between them will be A unchanged B doubled C quartered D quadrupled

D quadrupled

What method of heat transfer allows the Sun's heat energy to reach Earth through the vacuum of space? A condensation B conduction C convection D radiation

D radiation

What happens if you cut a magnet in half? A it becomes demagnetized B you get a separate south pole and a separate north pole C you get monopoles D you get two magnets

D you get two magnets

A piece of lead (c=0.13) gives off 1300J of energy and cools from 180°C to 90°C, what is the mass of the lead?

111.1

What is the temperature change in 180g of aluminum (c=0.9) if 2700J of energy is absorbed? Record your answer to the nearest tenth.

16.7

The Moon was much closer to Earth 4.6 billion years ago. Which of the following statements describes the gravitational interaction of Earth and the Moon 4.6 billion years ago? A The gravitational force of the Moon on Earth was larger than the force is now. B The gravitational force of Earth on the Moon was the same as the force is now. C The gravitational force of the Moon on Earth was smaller than the force is now. D The gravitational force of Earth on the Moon was smaller than the force is now.

A The gravitational force of the Moon on Earth was larger than the force is now

A father (100 kg) and his son (50 kg) are jogging at the same speed of 1 m./s. Which statement is true about the kinetic energies (KE) of the father and the son? A The kinetic energy of the father is two times the kinetic energy of the son. B The kinetic energy of the father is one-half the kinetic energy of the son. C The kinetic energy of the father is four times the kinetic energy of the son. D The kinetic energy of the father is one-fourth the kinetic energy of the son.

A The kinetic energy of the father is two times the kinetic energy of the son.

Ball A has a mass of 3 kg and was traveling east at 10 m/s when it collided with ball B. Ball B has the same mass as ball A, a mass of 3 kg, and was stationary before the collision as shown in the image below. The collision was elastic. What are the velocities of ball A and ball B after the collision? A The velocity of ball A is 0 m/s and the velocity of ball B is 10 m/s east. B The velocity of ball A is 10 m/s west and the velocity of ball B is 0 m/s. C The velocity of ball A will be 5 m/s west and the velocity of ball B will be 5 m/s east. D The velocity of ball A is 0 m/s and the velocity of ball B is 10 m/s west.

A The velocity of ball A is 0 m/s and the velocity of ball B is 10 m/s east.

Which of the following statements describes how an generator creates electricity? A magnet is rotated through a coil of wire to produce an electric current. B Electric potential in a rotating coil of wire creates a permanent magnet. C An electrical current causes a coil of wire to rotate in a magnetic field. D Forces from a permanent magnet allow a coil of wire to rotate.

A a magnet is rotated through a coil of wire to produce an electric current.

A current __________ in a stationary wire in an unchanging magnetic field. A is not produced B is easily generated C always exists D cannot exist

A is not produced

An electric generator converts __________. A mechanical energy into electrical energy B electrical energy into magnetic energy C magnetic energy into electrical energy D magnetic energy into chemical energy

A mechanical energy into electrical energy

In a baseball game, a batter hits a ball for a home run. Compared to the magnitude of the impulse imparted to the ball, the magnitude of the impulse imparted to the bat is A the same B greater C less D zero

A the same

Two different liquids (A and B) with equal mass are initially at the same temperature. They are heated for the same amount of time. You measure the temperatures and find that liquid A has a higher temperature than the other. Which liquid has a higher specific heat, in other words, which one has the higher heat capacity?

B

Which statement describes what most likely occurs when a magnetic compass is placed next to a simple circuit made from a battery, a light bulb, and a wire? A A magnetic field created by the compass causes the light bulb to stop working. B A magnetic field created by the electric current causes the compass needle to move. C A magnetic field created by the compass increases the current in the electrical circuit. D A magnetic field created by the electric current places negative charges on the compass.

B A magnetic field created by the electric current causes the compass needle to move.

At an amusement park, bumper car X moves at a speed of 2.5 m/s toward car Y, which is at rest, as shown in the diagram below. A Car X collides with car Y. How does the momentum of each car change after the collision? A Car X's momentum increases, and car Y's momentum decreases. B Car X's momentum decreases, and car Y's momentum increases. C Car X's momentum is unchanged, and car Y's momentum increases. D Car X's momentum is unchanged, and car Y's momentum decreases.

B Car X's momentum decreases, and car Y's momentum increases.

__________ is the generation of current due to relative motion between a wire and a magnetic field A Magnetic flux B Electromagnetic induction C Electrolysis D Electrospectrometry

B Electromagnetic induction

An iron bar is placed in a flame, as shown below, and is heated until the end glows. The other end of the iron bar soon becomes hot, too. Which of the following statements best describes what happens? A A convective flow of energy is set up inside the iron bar. B Energy is conducted from atom to atom along the length of the iron bar. C Radiation moves through the iron bar and is absorbed by the end not in the flame. D Air heated by the flame radiates down the iron bar and heats the end not in the flame.

B Energy is conducted from atom to atom along the length of the iron bar.

A cart at the top of a hill is released and rolls down the hill. Which of the following describes the energy of the cart just as it reaches the bottom of the hill? A The cart has no energy. B The cart has maximum kinetic energy. C The cart has maximum gravitational potential energy D The cart has equal gravitational potential and kinetic energy.

B The cart has maximum kinetic energy.

Which of the following is an example of heat transfer by conduction? A sunlight heating a floor B an electric stove heating an iron pan C a wood stove heating nearby objects through electromagnetic waves D an electric heater heating air, which rises and is replaced with cooler air

B an electric stove heating an iron pan

A- 1kg 4m/s B-2kg 2m/s C-.5kg 4m/s D-4kg 1m/s Which two objects have the same kinetic energy?

B and C

When one end of a short metal bar is heated, the opposite end will eventually become hot. Which of the following processes transfers the heat through the bar? A condensation B conduction C convection D radiation

B conduction

Cars are designed with crumple zones to prevent a car from hitting a wall and bouncing back in the opposite direction. In the event of front-end or rear-end crash, the crumple zones in cars are designed to A increase the change in velocity of the car. B decrease the change in velocity of a car. C decrease the time of impact during the crash. D change the mass of the car.

B decrease the change in velocity of a car.

Popcorn is made by heating corn kernels. Different methods may be used to heat the kernels. Which of the following methods uses radiation as the primary means of transferring energy to the corn kernels? A heating corn kernels in a hot air popper B heating corn kernels in a microwave oven C heating corn kernels in a foil pan on a hot plate D heating corn kernels in oil in a pot on an electric stove

B heating corn kernels in a microwave oven

The reason airbags are used in cars is that they A increase the force of impact in a collision B increase the time of impact in a collision C decrease the time of impact in a collision D they don't serve a purpose in cars.

B increase the time of impact in a collision

An electron is located in the electric field between two parallel metal plates as shown in the diagram below. If the electron is attracted to plate B, then plate B is charged A positively, and the electric field is directed from plate A toward plate B B positively, and the electric field is directed from plate B toward plate A C negatively, and the electric field is directed from plate A toward plate B D negatively, and the electric field is directed from plate B toward plate A

B positively, and the electric field is directed from plate B toward plate A

If a force of 100 Newton's was exerted on an object and no work was done, the object must have A accelerated rapidly B remained motionless C decreased its velocity D gained momentum

B remained motionless

The momentum change of an object is equal to the A velocity change of the object B the impulse acting on it C force acting on it D the mass of the object

B the impulse acting on it

As a rocket rises, its kinetic energy changes. At the time the rocket reaches its highest point, most of the kinetic energy of the rocket has been... A permanently destroyed. B transformed in to Potential Energy. C converted to friction. D stored in bonds between its atoms.

B transformed in to Potential Energy.

A motor produces less mechanical energy than the energy it uses because the motor A gains some energy through motion. B stores some energy as electrons. C converts some energy into heat and sound. D uses some energy to increase in mass.

C converts some energy into heat and sound.

Two positively charged objects are separated by a large distance. One of the positively charged objects is replaced by a negatively charged object, and the two objects are moved closer to each other. A The attractive force becomes a repulsive force, which increases as the objects move closer to each other. B The attractive force becomes a repulsive force, which decreases as the objects move closer to each other. C The repulsive force becomes an attractive force, which increases as the objects move closer to each other. D The repulsive force becomes an attractive force, which decreases as the objects move closer to each other

C The repulsive force becomes an attractive force, which increases as the objects move closer to each other.

In a television set with a cathode ray tube display, a beam of negatively charged particles called cathode rays passes by a positively charged plate. The beam is defl ected before it hits the television screen to produce an image. Which of the following changes would result in the greatest increase in the attraction between the negatively charged particles in the beam and the positively charged plate? A increasing the distance between the plate and the particles and increasing the charge on the plate B increasing the distance between the plate and the particles and decreasing the charge on the plate C decreasing the distance between the plate and the particles and increasing the charge on the plate D decreasing the distance between the plate and the particles and decreasing the charge on the plate

C decreasing the distance between the plate and the particles and increasing the charge on the plate

Which of the following sets of charges has the greatest attractive force when the charges are equal in magnitude? A two like charges placed 1 m apart B two like charges placed 2 m apart C two opposite charges placed 1 m apart D two opposite charges placed 2 m apart

C two opposite charges placed 1 m apart

Using ground level as the reference height with zero potential energy, which object has the greatest gravitational potential energy? A a 2-kg mass at 60-m height B a 5-kg mass at 5-m height C 20-kg mass at 50-m height D a 40-kg mass at 2-m height

C 20-kg mass at 50-m height

The 500 g cart is moving in a straight line at a constant speed of 2 m/s. Which of the following must the 250 g toy car have in order to maintain the same momentum as the cart? A An acceleration of 5 m/s2 for 2 seconds B A potential energy of 20 J C A constant velocity of 4 m/s D An applied force of 5 N for 5

C A constant velocity of 4 m/s

Which of the following statements best explains how heat flows by conduction? A A large mass of air begins to move faster. B Energy is transferred by electromagnetic waves. C Energy is transferred from molecule to molecule. D A large mass of warm air rises, replacing the cooler air above.

C Energy is transferred from molecule to molecule.

Calorimeters are instruments used to measure heat. The diagrams below show a calorimeter before a metal sample is added and after the sample is added. Which of the following statements describes the flow of heat energy after the metal sample is added? A Heat energy flows from the stirrer to the thermometer. B Heat energy flows from the water to the metal sample. C Heat energy flows from the metal sample to the water. D Heat energy flows from the insulation to the thermometer.

C Heat energy flows from the metal sample to the water.

The diagram below shows a simple electric circuit. Which of the following statements describes the function of the battery? A It reduces the flow of electrons. B It transmits light through the circuit. C It pushes electrons through the circuit. D It releases light during a chemical reaction.

C It pushes electrons through the circuit.

In trial 1, students measure the period of a pendulum. In trial 2, students increase only the mass of the pendulum and then again, measure the period. The period of the pendulum in trial 2 A Increase B Decrease C Not Change D There is not enough information predict any changes

C Not Change

An advertisement claims that a certain truck has the most powerful engine in its class. If the engine has more power, which of the following can the truck's engine do, compared to every other engine in its class? A Produce fewer emissions B Operate more efficiently C Perform faster work D Accelerate longer

C Perform faster work

The diagrams below show a cart moving with a velocity, V, on a frictionless surface as a wooden block is being dropped. The block then falls straight down onto the moving cart. A The cart will move to the left at a velocity less than the original velocity of the cart. B The cart will move to the left at a velocity greater than the original velocity of the cart. C The cart will move to the right at a velocity less than the original velocity of the cart. D The cart will move to the right at a velocity greater than the original velocity of the cart.

C The cart will move to the right at a velocity less than the original velocity of the cart.

A small insect collides and sticks to the windshield of a large car in a head on collision. Which of the following statements is NOT true? A The magnitude of the average force of impact on the car compared to the insect are the same B The magnitude of the impulses on the car compared to the insect are the same C The change in magnitude of the speed of the car compared to the insect are the same D The magnitude of the changes in momentum of the car compared to the insect are the same

C The change in magnitude of the speed of the car compared to the insect are the same

A magnetic compass is placed near an insulated copper wire. When the wire is connected to a battery, the compass needle changes position. Which of the following is the best explanation for the movement of the needle? A The copper wire magnetizes the needle to create a force. B The needle magnetizes the copper wire to create a force C The current in the wire produces a magnetic field and exerts a force on the needle. D The insulation on the wire becomes energized and exerts a force on the needle

C The current in the wire produces a magnetic field and exerts a force on the needle.

An electrostatic paint sprayer is used to spray paint evenly onto the surface of a car. Before the paint is sprayed, the car body is given a positive charge and the paint droplets are given a negative charge. The paint droplets experience an attractive force as soon as they are released from the sprayer. The paint droplets are originally sprayed at a distance of 30 cm from the car body, as shown below. Which of the following changes will cause the largest increase in the attractive force on the paint droplets A The charge on the car body is doubled. B The charge on the paint droplets is doubled. C The distance between the paint droplets and the car body is halved. D The distance between the paint droplets and the car body is doubled.

C The distance between the paint droplets and the car body is halved.

A horizontal force of 600 N is used to push a box 8 m across a room. Which of these variables must be known to determine the power used in moving the box? A The weight of the box B The potential energy of the box C The time it takes to move the box D The length of the box

C The time it takes to move the box

A student researches Jupiter and Saturn and records the following information: • Jupiter is about half the distance to the Sun that Saturn is. • Jupiter is about three times more massive than Saturn. Based on this information, which of the following can be concluded about the gravitational forces between these planets and the Sun? A There are no gravitational forces between Jupiter and the Sun or between Saturn and the Sun. B There are equal gravitational forces between Saturn and the Sun and between Jupiter and the Sun. C There is a greater gravitational force between Jupiter and the Sun than between Saturn and the Sun. D There is a greater gravitational force between Saturn and the Sun than between Jupiter and the Sun.

C There is a greater gravitational force between Jupiter and the Sun than between Saturn and the Sun.

The gravitational potential energy of an object is dependent on the object's A acceleration B momentum C height D speed

C height

liquid water-4.18 solid water (ice)-2.11 water vapor-2 dry air- 1.01 basalt-.84 granite- .79 iron-.45 copper-.38 lead-.13 The table of specific heats above shows various substances. If the same amount of heat energy were added to all of them, which substance would change temperature the fastest? (which would get hotter quicker?) A Copper B Water C Lead D Granite

C lead

As a ball falls freely (without friction) toward the ground, its total mechanical energy A decreases B increases C remains the same D zero

C remains the same

Magnetic fields can be produced by particles that are A moving and charged B moving and neutral C stationary and charged D stationary and neutral

C stationary and charged

A 1.0-kilogram laboratory cart moving with a velocity of 0.50 meter per second due east collides with and sticks to a similar cart initially at rest. After the collision, the two carts move off together with a velocity of 0.25 meter per second due east. The total momentum of this frictionless system is A zero before the collision B zero after the collision C the same before and after the collision D greater before the collision than after the collision.

C the same before and after the collision

Gravitation force direction

Direction is pointed towards the other object

A 3.0-kilogram object is placed on a frictionless track at point A and released from rest. (Assume the gravitational potential energy of the system to be zero at point C.) Which letter represents the farthest point on the track that the object will reach?

G (the same height as c)

Two wave pulses are traveling on a rope in opposite directions, as shown in the diagrams. The wave pulses have the same length and amplitude. When wave X meets wave Y, what will most likely be the appearance of the resulting pulse?

One big pulse

The distance between two charges is represented by d. In which of the following diagrams is the attractive force between the two charges the greatest?

Smallest distance and largest charge

Gravitational force distance

The distance between the centers of each object

Precise measuring instruments require shock absorbers to eliminate small vibrations that can affect the results of an experiment. One type of shock absorber that can be used is an electromagnet that repels a magnetic platform placed above it. Which of the following setups would provide the greatest lift to the platform?

The one with the most resistors and batteries

In a competition, weightlifter 1 lifts a 100 kg weight from the floor. Weightlifter 2 also lifts a 100 kg weight to the same height above the floor, but takes a longer time to do so.

Weightlifter 2 does the same work and uses less power compared with weightlifter 1.

A cup containing 25 mL of hot water and a similar cup containing 25 mL of cold water are placed on a table in a room at 21 degrees celsius. Which of the following graphs shows the most likely change in temperature for each cup from 0 min to 40 min?

hot above 21 going towards 21 cold below 21 going towards 21

when two magnets are facing each other (N and N)

its the strongest near the poles, weakest in the middle

What is the direction of a compass needle placed near the south of the magnet

left

more resistors in a series curcuit

less current

more resistors in a parallel circuit

more current

Which circuit is built so that if one light bulb goes out, the other three light bulbs will continue to glow?

parallel circuits

right hand rule (3)

pointer = current middle = magnetic field thumb = force

What is the direction of a compass needle placed below the magnet

right

Removal of which light bulb will interrupt the circuit and cause all the other light bulbs to fail to glow

the one connecting the circuit to the generator

The diagram below represents a bicyclist at the top of a hill, with four points labeled W, X, Y, and Z. Assume that the bicyclist does not apply the brakes as he rides down the hill. At which point will the bicyclist's kinetic energy be closest to zero?

the top

right hand rule (1 and 2)

thumb = current rotation of fist = magnetic field (and vis versa)

a compass needle points in the same direction as the magnetic field

true