PHYSICS FINAL

If your textbook is pulled to the right with a 15N while being pulled to the left with 5N, the net force on the book

10 N to the right

A body's inertia depends on its a. mass b. weight c. net force d. speed

A

A pair of 3-N and 4-N forces CANNOT have a resultant of a. 0 N b. 1 N c. 7 N d. but I can have any of these

A

A player hits a ball with a bat. The action force is the impact of the bat against the ball. What is the reaction to this force? a. the force of the ball against the bat b. the weight of the ball c. air resistance on the ball d. the drip of the players hand against the bat e. none of the above

A

Compared with falling on a wooden floor, a wine glass may not break when it falls on a carpeted floor because of a. longer time to stop b. lesser impulse in stopping c. both d. neither

A

If you push an object twice as far while applying the same force, you do a. twice as much work b. four times as much work c. the same amount of work

A

If you push for an hour against a stationary wall, you do no work a. on the wall b. at all c. both d. none of the above

A

The ultimate source of energy from fossil fuels is the a. sun b. radioactivity in Earth's interior c. photosynthesis process d. natural processes in Earth's interior

A

When you push an object a certain distance while applying twice the force, you do a. twice as much work b. four times as much work c. the same amount of work

A

Whenever an object exerts a force on another object, the second object exerts a force of the force of the same magnitude, but in the opposite direction to that of the first object. a. true b. false

A

You can't hurt yourself by punching a piece of paper because the a. paper cannot exert a large reaction force on you b. force of your hand on the paper is canceled by the force of the paper on your hand c. paper does not obey Newton's third law d. paper exerts no force on your hand

A

an archer shoots an arrow. consider the action force to be the bowstring against the arrow. the reaction to this force is the a. arrow's push against the bowstring b. weight of the arrow c. friction of the ground against the archers feet d. air resistance against the bow

A

an object that has kinetic energy must be a. moving b. falling c. at an elevated position d. at rest e. none of the above

A

an object that has kinetic energy must be a. moving b. falling c. at an elevated position d. at rest e. none of the above

A

the ultimate source of energy from fossil fuel is the a. sun b. radioactivity in earths inferior c. photosynthesis process d. natural processes in Earths interior

A

the momentum of an object is defined as the objects a. mass times its velocity b. force times the time interval c. forces times its acceleration d. mass times its acceleration e. velocity times the time interval

A (p=mv)

a 4-kg ball has a momentum of 12 kgm/s. What is the balls speed? a. 3m/s b. 4m/s c. 12m/s d. 48m/s

A (p=mv) 12kgm/s=(4kg)v 3m/s=v

what is the momentum of the object with a mass of 10kg traveling with a speed of 10m/s? a. 100kgm/s b. 1000kgm/s c. 100Ns d. 200kgm/s

A (p=mv) p=(10kg)(10m/s) p=100kgm/s

A freight train rolls along a track with considerable momentum. If it rolls at the same speed but has twice as much mass, its momentum is a. zero b. doubled c. quadrupled d. unchanged

B

It is correct to say that impulse is equal to a. momentum b. the change in momentum c. the force multiplied by the distance that forces acts d. all of the above e. none of the above

B

Newtons first law motion is also called as a. Law of Velocity b. Law of Inertia c. Law of Acceleration d. Law of gravity

B

Suppose a cart is being moved by a force. If suddenly a load is dumped into the cart so that the cart's mass doubles, what happens to the cart's acceleration? a. it quarters b. it halves c. it stays the same d. it double

B

Whenever an object exerts a force on another object, the second object exerts a force of the same magnitude, but in the opposite direction to that of the first object. a. sometimes true b. always true c. always false

B

a rocket is able to accelerate in the vacuum of space when it fires its engines. The force that propels the rocket is the force a. of the rocket on the exhaust gases b. of the exhaust gases on the rocket c. neither a or b

B

distance traveled is equal to average speed multiplied by a. distance b. time c. acceleration d. instantaneous speed

B

friction is a force that always acts a. perpendicular to an objects motion b. opposite to an objects motion c. in the same direction as an objects motion

B

the first scientist to discover the concept of inertia is a. Aristotle b. Galileo c. Newton d. Einstein

B

the force that propels a rocket is provided by a. gravity b. its exhaust gases c. Newton's laws of motion d. Area of the object

B

which of the following has the largest momentum relative to Earth? a. a tightrope walker crossing Niagara falls b. a pickup truck speeding along a highway c. a Mack truck parked in a lot d. a dog running down the street

B

which of the following is a problem that some people blame on technology a. improved transportation b. widespread pollution c. reduction of acid rain d. economic growth

B

using 1000J of work, a toy elevator is raised from the ground floor to the second floor in 20s. How much power does the elevator use? a. 20 W b. 50 W c. 100 W d. 1000 W e. 20,000 W

B (1000J/20s)

what is the impulse on a baseball with a force of 0.76 N in a time of 3s? a. 2.55 Ns b. 2.28 Ns c. 2.28 N d. 0.25 Ns

B (I=FT) I=(.76N)(3s) I=2.28 Ns

calculate the kinetic energy of a 49kg scooter moving at 30m/s a. 2200 N b. 22050 J c. 40 J d. 22J

B (KE=1/2mv2) KE=1/2(49)(30)

What is the speed of the rabbit if it runs a distance of 25m in 3s? a. 8333m/s b. 8.33m/s c. 80.33m/s d. 803.2m/s

B (V=d/t)

a girl pulls on a 10-kg wagon with a constant force of 20N. What is the wagons acceleration? a. .5 m/s2 b. 2 m/s2 c. 10 m/s2 d. 20 m/s2 e. 200 m/s2

B (a=f/m) a=20/10

what is the distance of a freely falling rock when it falls from rest in 5s? a. 100m b. 125m c. 145m d. 200m

B (d=1/2gt2)

a 4kg ball has a momentum of 20.0kgm/s. What is the balls speed? a. 0.2 m/s b. 5.0 m/s c. 20.0 m/s d. 80.0m/s e. none of the above

B (p=mv) 20kgm/s=(4kg)v 4m/s=v

a ball is moving at 4m/s and has a momentum of 48 kgm/s. What is the balls mass? a. 4kg b. 12kg c. 48kg d. 192kg

B (p=mv) 48kgm/s=m(4m/s) 12kg=m

It takes 40J to push a large crate 4m across a floor. The force exerted on the crate is a. 4N b. 10N c. 40N d. 160N e. 1600N

B (w=fd) 40=f(4) f=10

All freely falling objects a. are subject to the same gravitational force b. experience the force of air drag c. accelerate at the same rate d. have the same mass

C

Energy is changed from one form to another with no net loss or gain a. sometimes true b. always false c. always true

C

Forces always occur a. as single quantities b. by themselves c. in pairs d. in triplets

C

If object A exerts a force on object B, then a. object A and object B experience forces in opposite direction b. object A and object B experience forces of the same direction c. object B exerts a force on object A d. all of the above

C

If you do work on an object in half the time, your power output is a. half b. the same c. twice

C

One object has twice as much mass as another object. The first object also has twice as much a. velocity b. gravitational acceleration c. inertia d. all of the above

C

Potential energy is the energy an object has because of its a. density b. size c. location d. speed e. temperature

C

Terminal velocity is a. equal to the mass of the object times acceleration b. the velocity an object has when it stops moving, for instance when it hits the ground c. the velocity at which a falling object stops accelerating d. is the initial velocity of the object

C

The table cloth trick (video) shown in class explains a. atoms b. molecules c. inertia d. chemistry

C

When a cannon fires a cannonball at a given speed, the smaller recoil speed of the cannon is due to different a. forces b. times c. masses d. momenta

C

a simple machine CANNOT multiply a. force b. distance c. energy d. none of the above

C

an object that has kinetic energy must be a. at rest b. falling c. moving d. elevated

C

if you do work on an object in half the time, your power output is a. half b. the same c. twice

C

the conservation of momentum is closely related to a. Newtons first law b. Newtons second law c. Newtons third law

C

the unit of work is the a. watt b. meter c. joule d. newton e. second

C

exert 100J in 50s and your power output is a. 1/4 W b. 1/2 W c. 2 W d. 4 W

C (100J/50s)

How does acceleration of an object change in relation to its mass? It is a. directly proportional b. acceleration doesn't depend on mass at all c. inversely proportional d. directly and inversely proportional

C (a=F/m)

How does acceleration of an object change in relation to its mass? It is a. directly proportional b. acceleration doesn't depend on mass at all c. inversely proportional

C (a=f/m)

What is the acceleration of the object if the velocity is 50m/s in a time of 4s? a. 1250 m/s2 b. 125m/s2 c. 12.5m/s2 d. 120m/s2

C (a=v/t)

A jack system will increase the potential energy of a heavy load by 1000 J with a work input of 2000 J. The efficiency of the jack system is a. 10% b. 20% c. 50% d. 80%

C (output/input x100) 1000J/2000J x100

a 2-kg ball is thrown at 3m/s. what is the balls momentum? a. 2kgm/s b. 3kgm/s c. 6kgm/s d. 9kgm/s e. none of the above

C (p=mv) p=(2)(3)

power is defined as a. force on an object divided by the time the force acts b. work done times the time taken to do that work c. work done on an object divided by the time taken to do the work d. distance divided by the time taken to move that distance e. force on an object times the distance the object moves

C (p=w/t)

A hammer hits a nail. We'll call this the action. Which force is the reaction? a. the person swinging the hammer b. the hammer hitting the nail c. the hammer or the nail d. the nail hitting the hammer e. the person and the nail

D

A karate expert executes a swift blow and severs a brick with her bare hands. Equal magnitudes occur for the a. impulse on both the brick and the experts hand b. force on both the brick and the experts hand c. time of contact on both the block and the experts hand d. all of the above

D

An object may have potential energy because of its a. speed b. acceleration c. momentum d. location e. none of the above

D

The force of a falling apple hitting the ground depends upon a. the speed of the apple just before it hits b. the time of contact with the ground c. whether or not the apple bounces d. all of the above

D

The power expended for a barbell raised 2.0 m in 2 s is a. 1W b. 4W c. 8W d. not enough information

D

When you hit a wall, your hand gets sore because a. your hand exerts a force on the wall b. your skin exerts a force on your bones c. of the softness of your hand d. the wall exerts a force on your hand

D

every object continues in a state of rest or uniform motion in a straight line at a constant speed unless a net force acts on it is a. Newtons II law b. Newtons III law c. Galileo law d. Newtons I law

D

A 2-kg mass weighs 20N and is held 4m above the ground. Its potential energy relative to the ground is a. 8J b. 20J c. 60J d. 80J

D (PE=mgh) PE=(2)(10)(4)

A music console is pushed a distance of 2 m with a force of 20 N. The work done on the console is a. 2J b. 10J c. 20J d. 40J e. 80J

D (w=fd) w=(20N)(2m)

The force of friction between materials sliding against each other depends on a. the kind of material b. roughness of material c. the force with which they are pressed together d. all of the above

D.

As a pendulum swings back and forth a. at the end points of its swing, its energy is all potential. b. at the lowest part of its swing, its energy is all kinetic. c. kinetic energy is transformed into potential energy. d. potential energy is transformed into kinetic energy. e. all of the above

E

The unit of power is A) Newton B) Meter C) Joule D) Second E) Watt

E

a collision is considered elastic if a. there is no lasting deformation b. the objects don't stick together c. the objects that collide don't get warmer d. after the collision, the objects have the same shape as before the collision e. all of the above

E

a moving object has a. speed b. velocity c. momentum d. energy e. all of the above

E

physics is the most basic science because a. the foundation of biology is chemistry and the foundation of chemistry is physics b. it is about the nature of basic things like forces, energy, and motion c. the ideas of physics extend into more complex sciences d. you can do better understand science in general if you understand physics e. all of the above

E

in physics, work is defined as a. forces times time b. force divided by distance c. distance divided by time d. force divided by time e. force times distance

E (w=fd)

A theory is a. an educated guess that has yet to be proven by experiment b. a synthesis of a large collection of information including well-tested guesses c. close argument by competent observers of observations of the same phenomena d. a guess that has been tested over and over again and always found to be true e. a science story about atoms and molecules

b. a synthesis of a large collection of information including well-tested guesses

A hypothesis is a. the long side of a right triangle b. an educated guess that has yet to be proven by experiment c. close agreement by competent observers of observations of the same phenomena d. a guess that has been tested over and over again and always found to be true e. a synthesis of a large collection of information that includes guesses

b. an educated guess that has yet to be proven by experiment

which one of the following steps is NOT a part of the scientific method? a. perform experiments to test the predictions b. repeat the experiments until the answers match predictions c. formulate a general rule based on the predictions and experimental outcome d. make a guess about the answer to a problem and predict its consequences e. recognize a problem

b. repeat the experiment until the answers match the predictions

the equilibrium rule EF=0, applies to a. objects or systems in rest b. objects of systems in uniform motion in a straight line c. both of these d. neither of these

c. both of these

A scientific fact is a. something you believe is true because you have been taught it b. a guess that has been tested over and over again and always found to be true c. close agreement by competent observers of observations of the same phenomena d. an educated guess that has yet to be proven by experiment e. a synthesis of a collection of data that includes well-tested guesses

c. close agreement by competent observers of observations of the same phenomena

when the mass of an object is compared to its volume, the concept is a. mass b. weight c. volume d. density

d. density

the difference between speed and velocity most involves

direction

TRUE/FALSE a lever is a simple machine that can multiply energy

false (CANNOT)

TRUE/FALSE impulse is the product of force and mass

false (I=FT)

TRUE/FALSE if the mass of an object is 186kg and the force applied is 200N, the acceleration of the object is 107.5m/s2

false (a=f/m)

TRUE/FALSE The SI unit of mass is Newton?

false -Kg

In science, an educated guess is a

hypothesis

TRUE/FALSE A force can be simply be defined as a push or pull

true

TRUE/FALSE Pseudoscience is not a valid science

true

TRUE/FALSE Velocity is defined as distance/time

true

TRUE/FALSE energy cannot be created or destroyed but can be transformed from one form to another

true

TRUE/FALSE support force is also called normal force

true

TRUE/FALSE volume is the quantity of space an object occupies

true

TRUE/FALSE the unit of power is Watt

true

TRUE/FALSE the force of a 20kg mass with an acceleration of 2m/s2 is 40N

true (a=f/m)

TRUE/FALSE if the speed of the cart is 8m/s in 1.3s, the acceleration is 6.15m/s2

true (s=d/t)

the force due to gravity on a body is the bodys

weight