Semester One Physics Exam

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

force times distance

the acceleration of an atwood machine is always a. zero b. negative c. faction of acceleration of gravity d. greater than acceleration of gravity

fraction of acceleration of gravity

what force causes things to slow down and lose their energy as heat. a. friction b. tenstin c. gravitiational d. electrical

friction

Carl Lewis set a world record for the 100 m run with a time of 9.86 seconds. If, after reaching the finish line, Mr. Lewis walked directly back to his starting point in 90.9 s, what is the magnitude of his average velocity for the 200.0m? a. o m/s b. 1.10 m/s c. 1.98 m/s d. 5.60 m/s e. 10.1 m/s

0 m/s

a woman can lift barrels a vertical distance of 1 meter or can roll them up a 2 m long ramp to the same elevation. if she uses the ramp to do the same amount of work, how much force is applied to the barrel to move it to the same height? a. 1/4 b. 1/2 c. same amount d. 2 times as much e. 4 times as much

1/2 as much

if a rock on a cliff has a mass of 15 kg and is 50 m off the ground how much will the kinetic energy be when the rock is 25 m off the ground? a. 1/2 Ui b. 1/4 c. 4 times d. 2 times

1/2 the Ui

what is a vector expression a. 10 N b. 10 N east c. 7 kg d. 7 s

10 N east

A 1 kg apple falls from rest, 5 m to the ground. the apple hits the ground with an impact speed of about a. 10 m/s b. 20 m/s c. 40 m/s d. 7.07 m/s

10 m/s

if an object is pushed with 5 N of force to the right and also pushed with 7N of force to the left, what is the net force acting on the object a. 12 N right b. 2 right c. 12 left d. 2 left

2 N left

a piece of putty moving with 2 units of momentum strikes and sticks to a heavy bowling ball that is initially at rest. after the putty sticks to the ball, both are set in motion with a combined momentum that is a. less than 2 b. 2c. more than 2 c. not enoug info

2 units

estimate the amount of power needed to lift a 10 kg box 2m in 1 second a. 50 b. 5 W c. 20 d. 230 e. 200

200 W

a net force is required to give an object with mass m an acceleratino a. if a net force 6 F is applied to an object with mass 3 m what is the acceleration on this object? a. a b. 2a c. 3a d. 4a e. 6a

2a

an olympic athlete throws a javelin at four different angles above the horizontal, each with the same speed, 30, 40, 60, and 80 degrees. which two throws cause the javelin to land the same distance away a. 30 and 80 b. 40 and 60 c. 40 and 80 d. 30 and 60

30 and 60 degrees

a police car is in pursuit of a stolen pickup truck. at one instant, the car has a speed of 35 m/s and is 150 m behind the truck. at the same time, the truck has a speed of 30 m/s if neither vehicle accelerates, how long will it take the police to catch the pickup truck? a. 5 s b. 65 s c. 30 s d. 82 s e. 50 s

30 seconds

a motorcycle has a velocity of 15 m/s due south, as it passes a car with a velocity of 24 m/s due north. what is the magnitude and direction of the velocity of the motorcycle as seen by the driver of the car? a. 9 m/s north b. 9 m/s south c. 15 m/s north d. 39 m/s south e. 39 m/s south

39 m/s south

you pull horizontally on a 50 kg crate with a force of 450 N and the friction force on the crate is 250 N. the acceleration of the crate is a. 2 m/s^2 b. 9 c. 4 d. 14

4 m/s^2

a person is attracted towards the center of the earth by a 440 N gravitational force. the force with which the earth is attracted toward the person is a. 440 N b. very very small c. very very large

440 N

a woman stands on the edge of a cliff and throws a stone vertically downward with an initial speed of 10 m/s. the instant before the stone hits the ground below, it has 450 J of kinetic energy. if she were to throw the stone horizontally outward from the cliff with the same initial speed of 10 m/s, how much kinetic energy would it have just before it hits the ground? a. 0 j b. less than 450 c. 450 e. greater than 450

450 J

if you push with 6 N on an object to the right along a surface of a table and it moves at a constant velocity of 2 m/s, determine the magnitude friciton force on the object a. 0 N b. 12 c. 6 d. 3

6 N

what is the estimate weight of a kid that has a mass of 66 kg? a. 660 N up b. 660 N down c. 660 kg down d. 660 N down e. 66 kg up

660 N down

how much force is need to accelerate a 4 kg physics book to an acceleration of 2.0 m/s^2 a. 0 N b. .5 c. 2 d. 8 e. 24

8 N

compared to yesterday, you did 3 ties the work in one third the time. to do so, your power output must have been a. same as yesterday b. one third c. 3 times d. 9 times

9 times yesterday's power output

correct value and uncertainty : winning time in a race as measured with a stop watch 9.43 s

9.4 s +/- .5 s

correct value and uncertainty: a students height with a meter stick (1 mm) 98.22 cm

98.22 cm +/- .05 cm

correct value and uncertainty: mass of an apple on a digital scale 98.23 g

98.23 g +/- .01 g

10 N force is applied to push a block across a friction free surface for a displacement of 5 m to the right, determine which forces have done work on them a. f norm cb. f app c. f grav

Fapp

which is accurate? a. vector cannot have zero magnitude if one of its components is not zero b. magnitude of vecor can be less than magnitude of one of its components c. magnitude of vecor a is less than magnitude of vector b, x component of a is less than x component of b d. magnitude of a vector can be positive or nagative

a

two vectors a and b are added together to form a vector c. the relationshiop between the magnitudes of the vectors is given by a + b = c. what is true concerning these vectors? a. a an db must be displacements b. equal lenghts c. point in opposite directions d. same direction e. right angles

a and b must point in the same direction

What is an example of a projectile? a. cannonball thrown straight up b. cannonball rolling down a level street c. cannonball rolling off edge of table d. cannonball dropped from side of cliff e. all are examples

a cannonball rolling off the edge of a table

the horizontal component of a projectiles velocity is a. effected by acceleration of gravity b. constant value throughout trip c. zero throughout motion of object

a constant value throughout the trip

Ball a is dropped from rest from a window. at the same instant, ball b is thrown downward and ball c is thrown upward from the same window. what is true about the balls after their release if air resistance is neglected a. at some instant after thrown, acceleration of ball c is zero b. strike ground at same time c. all three balls have same velocity d. same acceleration at any instant e. reach ground with same velocity

all three balls have the same acceleration at any instant

A new car manufacturer advertises that their car can go from zero to sixty in eight seconds. What is this a description of? a. average speed b. instantaneous speed c. average acceleration d. instantaneous acceleration

average acceleration

decrease in gravitational potential energy a. boy stretches horizontal spring b. girl jumps down from bed c. crate rests at bottom of inclined plane d. car ascends a steep ill e. water is force upward through a pipe

b

which has more kinetic energy? a. elephant sleeping b. samall mouse flying through the air at 100 m/s c. normal cat running behind mouse at 10 m/s

b

two balls are thrown horizontally with different speeds. which one is in the air longer a. faster object b. slower object c. both at the same time

both at the same time

a cannon recoils from launching a cannonball. the speed of the cannons recoil is small because the a. impulse on cannon is less than impulse on cannon ball b. cannon has far more mass than cannonball c. momentum of cannon i sunchanged d. force against cannon is relativelty small

cannon has far more mass than the cannonball

when a projectile is shot up at a 45 degree angle from the ground the speed in the horizontal direction will ( ) and the speed in the vertical direction will ( ) on the way up and then ( ) on the way down a. constant, decrease, increase b. increase, decrease, increase c. decrease, increase, decrease d. constant, increase, decrease

constant, decrease, increase

two displacement vectors have magnitudes of 5 m and 7m respectively, when these two vecotrs are added, the magnitude of the sum a. 2 m b. between 2 and 12 m c. 12 m d. larger than 12 m

could be any value between 2 and 12 m

in which situation is zero net work done a. ball rolls down an inclined plane b. physics student stretches a spring c. projectile falls toward earth d. box is pulled agress a rough floor at a constant velocity e. child pulls wagon across rugh surface and accelerates

d.

when the angle of an incline with a block resting on it increases, the normal support force a. increases b. decreases c. stays the same

decreases

What is a vector quantity? a. time b. average speed c. displacement d. length e. distance

displacement

in all machines energy is lost in one form or another. there for there is no perpetual motion machine, so the only way to keep a machine going is to a. do work on the system b. add more friction c. do nothin gto it d. add more inertia

do work on the system

pendulum swings back an dforth a. 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 d. potential is transformed into kieti e. all of the above

e

a stone is thrown straight up. at the top of its path, the net force acting on it is a. greater than its weight b. greater than zero but less than its weight c. instanteaneously equal to zero d. equal to its weight

equal to its weight

you are trying to cross a river that flows due south with a strong current. you start out in your motorboat on the east bank desiring to reach the west bank directly west from your starting point. you should head your motorboat a. due west b. due north c. southwest d. north west

in a northwesterly direction

a bicylist is riding at a constant speed along a straight line path. the rider throws a ball straight up to a height a few meters abover her head. ignoring air resistance where will the ball land? a. behind rider b. infront of rider c. in the same hand that threw the ball d. opposite hand to the one that threw it e. cant be determined

in the same hand that threw the ball

a block is at rest on an incline. the force of friction neccessary to prevent the block from sliding increases when the incline angle is a. increased b. decreased c. neither a or b

increased

what term is used to indicate the natural tendency of an object to remain at rest or in motion at a constant speed along a straight line? a. velocity b. force c. accerlation d. equilibrium e. inertia

inertia

When you look at the speedometer in a moving car, you can see the car's a. average distance traveled b. instantaneous speed c. average speed d. instantaneous speed e. average acceleration

instantaneous speed

if bronco billy the skydiver is falling he is losing potential energy as he gets closer to the ground, but after a while he stops accelerating. so what is happening to the energy? a. destroyed b. transformed into greatter kinetic energy c. transormed into greater thermal energy

is is transformed into greater thermal energy

a physics student adds two displacement vectors with magnitudes of 8 km and 6 km. what is true concerning the magnitude of the resultant displacement? a. 10 km b. 14 km c. equal to zero depending on orientation d. no conclusion e. any value between 2 and 14

it could have any value between 2 km and 14 km depedning on how the vectors are orientated

when a football in a field goal attempt reaches its maximum height, how does its speed compare to its initial speed? a. zero b. less than initial speed c. equal to is d. greater than is

it is less than its initial speed

what is the correct unit of work expressed in SI units? a. kgm/s^2 b. kg m^2/s C kgm^2/s^2 cd. kg^2m/s^2

kg m2/s2

an unfortunate bug splatter against the winshield of a moving car. compared to the decelertaion of the car, the deceleration of the bug is a. larger b. same c. smaller

larger

a ball is thrown into the air with 100 J of kinetic energy, which is transformed to gravitational potential energy at the top of its trajectory. when it returns to its orginial level after encountering air resistance, its kinetic energy is a, 100 J b. more than 100 c. less tan 100 d. not enough info

less than 100 J

an airplane flying into a head wind loses ground speed and an airplane flying with the wind gains ground speed. if an airplane flies at right angles to the wind, then ground speed is a. more b. unchanged c. less

more

in the absence of an external force, a moving object will a. stop immediately b. slown down and come to a stop c. go faster and faster c. move with constant velocity

move with constant velocity

two cars collide head on. at every moment during the collision, the magnitude of the force the first car exerts on the second is exactly equal to the magnitude of the force the second car exerts on the first. this is an example of a. newtons first law b. second law thrid law newtons law of gravitation

newtons third law

Objects a and b accelerate from rest with the same constant acceleration. Object a acclerates for twice as long. What is true concerning these objects at the end of their respective periods of acceleration?

object a will travel four times as far as object b

a red marble moving to the right at 4 m/s has a head on elastic collisoin with a blue marble of the same mass sitting at rest on a smooth level surface. what is the correct magnitude and direction of the vellocities of the two marbles after the collision?

red marbles - zero m/s, blue marble- .40 m/s right

if you push twice as hard against a stationary brick wall, the amount of work you doa. doubles b. cut in half c. constant but non zero d. zero

remains constant at zero

a stunt person jumps from the roof of a tall building but no injury occurs because the person land on a large ari filled bag. what describes why no injury occurs a. bag provedes force to stop person b. reduces impulse c. increases time and reduces change in momntum d. increases amount of time which momentuam is changing and reduces the force on person e. increaes amount of time in which mometum is changeing and reduce force on person

the bag increases the amount of tim eduring which the momentum is changing and reduces the average force on the person

In what situation does a car have an eastward acceleration a. westward at constant speed b. westward and speeds up c. eastward and slows down d. westward and slows down e. starts from rest and moves west

the car travels westward and slows down

a particle travels along a curved path from point P to point Q. the velocity of the particle does not depend on a. location of p b. location of q c. distance travled from p to q d. shortest distance between p and q e. direction of q from p

the distance traveled from P to Q

a rock is thrown straight up from the surface of the earth. what is true of the energy transformation of the rock as it rises? a. total energy increases b. kinetic energy increases and potential decreases c. potential and total energy increase d. kinetic energy decreaes and potential increases e. both remian

the kinetic energy decreases and the potential energy increases

two objects constitute an isolated system. in an elastic collision between the two object, what is false a total kinetic enrgy is conseved b. kinetic energy of each object is the sam before an dafter the collision c. total moentum is conserved c. magnitude of the foce exerted by each object on the other is equal e. total kinetic nergy before collision is equal to the total kinetic energy after the collision

the kinetic energy of each object is the same before and after the collision

why is it more important to have seat belts in a car then in a bus a. larger masss of bus will cause smaller change in velocity and kids inertia keeps them in place b. larger mass will cause larger change in vlocity c. bus drivers dont drive crazy

the larger mass of the bus will cause a smaller change in velocity and so the kids inertia won't cause them to fly out of the window

two balls of equal size are dropped from the same height from the roof of a building. one ball has twic the mass of the other. when the balls reach the ground, how do the kinetic energies of the two balls compare? a. lighter one has one fourth as much as other b. lighter one has one half lighter one has same d. lighter one has twice e. lighter one has four times

the lighter one has one half as much kinetic energy as the other does

a space vehicles has mass m and spped v. at some instant, it seperates into two pieces each with a mass of .5 m. one of the pieces is at rest just after the seperation. whaat is true regarding this situation a. moving piece has speed 2v b. process converves kinetic enrgy c. piece at rest possesses kinetic enrgy d. process does not conserve total energy e. process does not conserve momentum

the moving piece has speed 2v

an elevator supported by a single cable descends a shaft at a constand speed. the only forces acting on the elevator are the tension in the cable and the gravitational force. what would be true in this situation a. magnitude of work done by tension is larger than that done by gravity b. magnitude of work donw by gravity is larger than that done by tension force c. work done by tension force is 0 d. work done by gravity is 0 e. net work done by two forces is 0

the net work done by the two forces is zero jules

A spring loaded gun is aimed horizontally and is used to launch identical balls with different initial speeds. the gun is ata fixed position above the floor. the balls are fired one at a time. if the speed of the second ball fired is twice the speed of the first balll fired, how is the horizontal range affected? a. range is same for both b. range of second ball is half as much c. range of second ball is twice as large d. range of second ball is 1.4 times larger e. range of second ball is smaller than first ball by a factor of 1.4

the range of the second ball will be twice as large as that of the first ball

A rock is thrown vertically upward from the surface of the earth. The rock rises to some maximum height and falls back toward the surface fo the earth. What is true about this situation if air resistance is neglected? a. rock rises, acceleration vector points upward b. rock is a freely falling body for duration of flight c. acceleration of rock is zero when rock is at highest point d speed is negative when ball falls back to earth e. velocity and acceleration are in same direction

the rock is a freely falling body for the duration of its flight

Starting from rest, a particle confined to move along a straight line is acclerated at a rate of 5 meters per second. what does the slope of the position versus time graph look like? a. constant value of 5 m/s b.. constant value of 5 m/s^2 c. constant and negative d. not constant increases with increasing time e. not constant and decreases with increasing time

the slope is not constant and increases with increasing time

A ball is thrown vertically upward from the surface of the earth. What values of the ball are zero when the ball has reached the maximum height: speed, velocity, or acceleration a. speed and velocity b. speed and acceleration c. speed d. velocity e. all

the speed and the velocity of the ball

starting from rest a particle confined to move along a straight line is accelerated at a rate of 5 m/s^2. what accuratly describes its motion a. particle travels 5 m during each second b. particle travels 5 m only during first second c. speed increases by 5 m/s during each second d. acceleration increaes by 5 m/s^2 during each second e. final speed is proportinal to the distance

the speed of the particle increases by 5 m/s during each second

a stone is thrown horizontally from the top of a tower at the same instant a ball is dropped vertically. which object is traveling faster when it hits teh level ground blow? a. impossible to tell b. stone c. ball d. neither

the stone

which is a scalar quantity? a. velocity of earth b. acceration c. pull of earth d. temp of ice cream e. displacement

the temperature of ice cream

a rock is suspended from a string and is moving upward at a constant velocity. what is true concerning the tension in the string if air resistance is ignored a. tension is zero newtons b. tension points downwards c. tension is equal to the weight of the rock d. tension is less than the weight of the rock e. tension is greater than the weight of the rock

the tension is equal to the weight of the rock

a rock is suspended from a string and moves downward at an accelerated rate. what is true concernign the tension in the string if air resistance is ignored? a. tension is zero b. tension points down c. tnesion is equal to weight d. tension is less tan the weight e. tension is greater than weight

the tension is less than the weight of the rock

stationary firework explodes in space, breaking into a number of small fragmetns. at the location of the explosion, the net force due to gravity is zero newtons. what is true concerning this event a. kinetic energy is conserved b. fragments must have equal kinetic energyies c. sum of kietic enrgies of fragmest 0 d. vecotor sum of linear momenta of gragmesnts must be zero e. velocity of any one gragmest must be equal to the velocity of any other fragmesnt

the vector sum of the linear momenta of the fragements must be zero

a baseball is hit upward and travels along a parabolic arc before it strikes the gound. what is true about this situation? a. acceleration of ball decreases as ball moves up b. velocity of ball is zero at highest point c. acceleration is zero when at highest point d. x component is same throughout e. velocity of ball is maximum when ball is at highest point

the x component of the velocity of the ball is the same throughout the balls flight

a bullet is fired horizontally and at the same instant a second bullet is dropped from the same height. ignore air resistance. compare the times of fall of the two bullets a. fired bullet hits first b. dropped bullet hits first c. hit at same time d. can't tell without mass

they hit at the same time

if you lift one load up two stories, how much work do you do compared to lifting one load up only one story? a. on equarter as much b. one half c. same amount d. twice e. four times

twice as much

you are standing in a moving bus, facing forward, and you suddenly fall forward you can imply from this that the buses a. velocity decreased b. velocity increased c. speed remained the same, but its turning to the right d. speed remained the same, but its turning to the left

velocity decreased

a rocket moves through empty space in a straight line with constant speed. it is far from the gravitational effect of any star or planet. under these conditions, the force that must be applied to the rocket in order to sustain its motion isa. equal to its weight b. equal to its mass c. dependent on how fast it is moving d. zero

zero