Physics Semester 1 Final

A cart is given an initial velocity at 11 m/s and experiences a constant acceleration of 2. What is the car's displacement during the first 5 of its moving?

80m

the kinetic energy of a car is 8x10^6 J as it travels along a horizontal road. How much power is required to stop the car in 10s?

8x10^5

Suppose there is some quantity "S", what does Sigma S mean?

S1+S2+S3...

If the momentum of an object changes and its mass remains constant (its velocity changes; it is accelerating or decelerating; there is a force acting on it; or all of the above)

all of the above

A skater spins with her arms and one leg outstretched. When she pulls in her arms and leg, she will spin faster. This can be explained using the law of conservation of

angular momentum

A group of figure skaters are rounding a corner. Each skater has to have the same...

angular velocity

Compared to a sports car moving at 30 miles per hour, the same sports car moving at 60 miles per hour has

twice as much momentum

acceleration is a physical quantity measured in m/s^2. If x is measured in m, v is measured in m/s and t is measured in s, what has the same units as acceleration

v/t^2

Displacement is which of the following types of quantities? (vector, scalar, magnitude, or dimensional)

vector

the motion of a ball on an inclined plane is described by the equation delta x =1/2 a(t)^2. This statement implies what has a value of zero?

vi

A traveler has about $536 in his checking account, about $2107 in his savings account and $7.62 in his wallet. To the greatest appropriate precision, how much money does this shopper have?

$2651

A candy shop sells a pound of chocolate for $10.85. What is the price of 1.5kg of chocolate at the shop?

$35.84

a 5kg block of ice is sliding across a frozen pond at 2 m/s. A 7.6 N force is applied in the direction of motion. After the ice block slides 15m, the force is removed. The work done by the applied force is

(+) 114 J

A 200kg car moving at 6 m/s collide with a 400kg car at rest. If the collision is inelastic, what is the velocity of the two cars tangled together after the collision?

2 m/s

An elevator is moving upward with a speed of 11 m/s. Three seconds later, the elevator is still moving upward, but its speed has been reduced to 5 m/s. What is the acceleration of the elevator during the 3s ninterval.

-2

A wheel, originally rotating at 126 rad/s decelerates to 98 rad/s while going through 627 radians. What is its angular acceleration?

-5 rad

A ball is thrown straight up. At top of its path its acceleration is

-9.8

convert 1.2x10^-2 to decimal notation

0.0120

If a computer screen has an area of 1.27 ft, this area is closest to

0.118m

An object requires 100s to rotate 20 times. Its angular velocity is

0.2 rev/s

Two ice skaters suddenly push off against one another starting from a stationary position. The 45-kg skater acquires a speed of 0.375 m/s relative to the ice. What speed does the 60-kg skater acquire relative to the ice?

0.281 m/s

A phonograph record 30cm in diameter rotates 33 and 1/3 times per minute. What is the speed of a point on its rim?

0.467 m/s

what is the maximum distance we can shoot a dart from ground level, provided our toy dart gun gives a max initial velocity of 2.78 m/s and there's no air resistance

0.789m

What is 0.674 / 0.74 to the proper number of significant figures?

0.91

A vehcile designed to operate on a drag strip accelerates from zero to 30 m/s while undergoing a straight line path displacement of 45m. what is the vehicle's acceleration if its value may be assumed to be constant?

10

a train approaches a small town with a constant velocity of +28.6 m/s. The operator applies the brakes reducing the train's velocity to +11.4 m/s. If the average acceleration of the train during braking is -1.65, for what elapsed time is the brake applied?

10.4 s

During a collision with a wall, the velocity of a 0.2000kg ball changes from 20 m/s toward the wall to 12 m/s away from the wall. If the time the ball was in contact with the wall was 0.06s what was the magnitude of the average force applied to the ball?

107N

a 20N force and a 30N force act on an object in opposite directions What is the net force on the object?

10N

Estimate how many shoes you could lay heel to toe in a line across this classroom

10^2

A car and a truck approach a right angle intersection and then suddenly collide. After the collision, they become entangled. The car was 1000kg and driving North, the truck was 4000kg and driving East both were driving at 13 m/s, find the madnitude and direction of the final velocity of the wreck.

11 m/s at 14º North of East

At a horizontal distance of 45m from a tree, the angle of elevation from the ground to the top of the tree is 14 degrees How tall is the tree?

11m

A certain aircraft has a mass of 300,000 kg. At a certain instant during its landing, its speed is 27.0 m/s. If the braking force is a constant 445,000 N, what is the speed of the airplane 10.0 s later?

12 m/s

An 810kg car accelerates from rest to 27 m/s in a distance of 240m. What is the most nearly the magnitude of the net force acting on the car?

1230 N

a flare fired straight up at 52.0 m/s will reach a maximum height of

138m

a projectile is fired horizontally from a height of 20 meters above the ground, with an initial velocity of 7 m/s. How far does the projectile travel horizontally before it reaches the ground?

14m

A 5N force acts on a 8kg objects for 3 seconds. What impulse is given to the object?

15 Ns

Find the length of the resultant of two vectors: A=9.00km; B=8.5km; B is a straight line and A is 60 degrees away from B

15.2km

a rock is kicked horizontally at a speed of 10 m/s from the edge of a cliff. the rock strikes the ground 55m from the foot of the cliff of height H, and is in the air for 5.5s. What is the approximate value of H?

150m

A ball is pushed with an initial velocity of 3.0 m/s. The ball rolls down a hill with a constant acceleration of 1.6 m/s^2. The ball reaches the bottom of the hill in 8.0 s. What is the ball's velocity at the bottom of the hill?

16 m/s

A car traveling at 20 m/s rounds a curve so that its centripetal acceleration is 2.5. What is the radius of the curve?

160m

A string is wrapped around a pulley of radius 0.025m and moment of inertia 0.2. If the string is pulled with a force F, the resulting angular acceleration of the pulley is 2. Determine the magnitude of the force F.

16N

a gymnast leaves a trampoline with a velocity of 6.7 m/s upward. What will be the maximum height she reaches?

2.3 m

An arrow is shot upward with an initial velocity of 15 m/s. After how much time is the arrow moving downward at 8 m/s

2.35 s

A helicopter (m=1250kg) is cruising at a speed of 25 m/s at an altitude of 185 m. What is the total mechanical energy of the helicopter?

2.66x10^6 J

A ball (mass 0.40 kg) is initially moving to the left at 30 m/s. After hitting the wall, the ball is moving to the right at 20 m/s. What is the impulse of the ball receives during its collision with the wall?

20 kg m/s to the right

An 800-kg car coasts down a hill 40m high with its engine off and its driver's foot is pressing on the brake pedal. At the top of the hill, the car's speed is 6 m/s. If the care loses 168,000 J of energy to friction on the way down, find it's speed at the bottom.

20 m/s

What is the value of pi(8.104)^2 written with the correct number of significant figures?

206.3

A rectangular garden measures 15m long and 13.7m wide. What is the length of a diaganol from one corner of the garden to the other?

20m

A 50kg box is being pushed along a horizontal surface. The coefficient of static friction between the box and the ground is 0.65, and the coefficient of kinetic friction is 0.35. What horizontal force must be applied on the box for it to start accelerate at 1.2?

230 N

a horizontal rifle is fired from 2m above ground level. if the bullet strikes the ground 150m away find the muzzle velocity

235 m/s

In the sport of platform diving, a platform is set at a height of 7.3m above the surface of the water. What is the height expressed in feet, of the platform?

24 feet

A rocket explodes into two fragment, one 25 times heavier than the other. The magnitude of the velocity of the lighter fragment is

25 times as great as the velocity of the heavier fragment

A woman weighing 500 N runs up a flight of stairs in 5s. Her net upward displacement is 5m. How much work did she do against gravity?

2500 J

A bat strikes a 0.15kg ball pitched at 40 m/s. The bat reverses the ball's direction and gives it a speed of 50 m/s. What average force does the bat apply to the ball if they are in contact for 0.054s?

250N

the kinetic energy of an 1100kg truck is 4.5x10^5 J. What is the speed of the truck?

29 m/s

A 0.508m diameter circular saw blade rotates at a constant angular speed of 117 rad/s. What is the tangential velocity of the tip of a saw tooth at the edge of the blade?

29.7 m/s

A bicycle travles 36m along a circular track of radius 12m. What is the angular displacement in radians of the bicycle from its starting position?

3 rad

A 2100kg car traveling 27 m/s makes a head-on collision with a 3200kg car traveling 12 m/s in the opposite direction. If the collision takes place on slick ice and the cars stick together after the collision, find their common speed after the collision

3.45 m/s

If a particle has a velocity of 8.4 mph, it's velocity in m/s is closest to

3.8 m/s

Which requires a lager change is KE, increasing a car's speed from 0 m/s to 30 m/s or from 30 m/s to 60 m/s?

30 m/s to 60 m/s

A girl whose weight is 600 N hangs from a bar supported by two parallel strands of rope. What is the tension in each strand?

300 N

mike is cutting the grass using a human powered lawn mower. he pushes the mower with a force of 45N directed at an angle of 41º below the horizontal direction. Calculate the work that mike does on the mower in pushing it 9.1m across the yard.

310J

A 50kg box is being pushed along a horizontal surface. The coefficient of static friction between the box and the ground is 0.65, and the coefficient of kinetic friction is 0.35. What horizontal force must be applied on the box for it to start moving?

320 N

A roadway for stunt drivers is designed for racecars moving at a speed of 40 m/s. A curved section of the roadway is a circular arc of 230m radius. The roadway is banked so that a vehicle can go around the curve with the friction force from the road equal to zero. At what angle is the roadway banked?

35º

A box has dimensions 18.5cm by 16.47cm by 12.2cm. Using the accepted rules for significant figures, the volume of the box is

3720cm

Mt. Everest is more than 8000m high. How fast would an object be moving if it could free fall to sea level after being released from an 8000m elevation?

396 m/s

How much force is needed to accelerate a 4.5kg physics book to an acceleration of 0.66?

3N

if Skelly the skater's speed increased so he has twice the momentum, then his kinetic energy is increased by

4

A rock is thrown straight down with an initial velocity of 14.5 m/s from a cliff. What is the absolute value of rock's displacement after 2s?

49m

Suppose a car is moving in a straight line and steadily increases its speed. It moves from 35 m/s to 40 m/s the first second and from 40 m/s to 45 m/s the next second. What is the car's acceleration?

5 m/s

a rock is kicked horizontally at a speed of 10 m/s from the edge of a cliff. the rock strikes the ground 55m from the foot of the cliff of height H, how long is the rock in the air?

5.5s

A certain merry-go-round is accelerated uniformly from rest and attains an angular speed of 2 rad/s in the first 10 seconds. If the net applied torque is 1000N*m, what is the moment of inertia of the merry-go-round?

5000

A quarterback throws a pass at an angle of 35 degrees above the horizontal with an initial speed of 25 m/s The ball is caught by the receiver 2.55 seconds later at the same height it was thrown from. Determine the distance the ball was thrown

52m

A 2.50kg stone on a string is whirled in a horizontal circle of radius 1.5m at a speed of 5.75m/s. Find the tension in the string

55.1N

What is the momentum of a 373 kg bumper car moving at 1.5 m/s?

560 kg m/s

An astronaut weighs 20N in orbit some distance from the center of the earth. If she moved 2 times as far from the center of the earth, her weight would become

5N

When the net force that acts on a hockey puck is 250N, the puck accelerates at a rate of 50. determine the mass of the puck

5kg

An astronaut weighs 99N on the moon, where the acceleration of gracity is 1.62. how much does she weigh on earth?

600 N

A 2.3kg object is traveling at 6.1 m/s East collides head on with a 3.5 kg traveling in the opposite direction at 4.8 m/s. The 3.5kg object recoils East at 3.89 m/s, what is the final speed of the 2.3 kg object?

7.1 m/s

A block weighing 20N is being pushed across a horizontal table by an 18N force. If the coefficient of kinetic friction between the block and table is 0.135, find the acceleration of the block

7.5

an airplane is flying with a velocity of 7.5 m/s east. a man dashes across the wing with a velocity of 2.5 m/s south. which is most nearly the magnitude of his velocity as seen by someone on the ground?

8 m/s

Two physical properties, A and B, have different units. Which of the following expressions could be physically meaningful?

B/A

A car travels at constant speed v in a circle of radius r. Which of the following statements are true? A) The car's angular velocity is rv B) The car has a non-zero tangential acceleration C) The car has a constant magnitude of centripetal acceleration D) The car travels at constant speed and has no acceleration E) none of the above statements are true

C

A small car meshes with a large truck in a head-on collision. Which of the following statements concerning the absolute value of the momentum change during the collision is correct? A) the truck experiences the greater absolute value momentum change B) The small car experiences the greater absolute value momentum change C) The small car a truck experience the same absolute value momentum change

C

Acceleration is defined as the

Change in velocity divided by the time interval

Which of the following is NOT properly matched? A) s, theta B) v, w (omega) C) F, tau (torque) D) m, I E) mark this if all the above are properly matched

E

An object is thrown straight up into the air and the only thing influencing its motion is gravity. How does the velocity change?

Its velocity changes by 9.8 m/s each second its in the air

A student with mass M is standing on a wooden plank of a mass m that is less than the mass of the student. The plank itself is resting on the frictionless surface of a frozen lake. The student then begins to walk with a speed v toward the nearby shore. What is the velocity of the plank relative to the shore?

More than v away from the shore

When a 45-kg person steps on a scale in an elevator, the scale reads a steady 480 N. Which of the following statements must be true? (the elevator... accelerates up; accelerates down; moves upward at a constant rate; or moves down at a constant rate)

accelerates up

the total amount of energy in the universe

cannot change

Complete the following statement: When a net torque is applied to a solid object, it always produces a

change in angular velocity

A racing car is moving around the circular track of radius 300m shown above. At the instant when the car's velocity is directed due east, its acceleration is directed due south and has a magnitude of 3 meters per second squared. When viewed from above, the car is moving

clockwise at 30 m/s

You are standing on a skateboard, initially at rest . A friends throws a very havey ball towards you. You have two choices about what to do. Either catch the ball or deflect it back toward your friend with the same speed as it was originally thrown. Which choice should you make in order to maximize your speed on the skateboard?

deflect the ball back

a vector has x and y components that are opposite in sign. the vector must point to which quadrants

either 2nd or 4th

You swing a bat and hit a heavy box with a force of 1500 N. The force the box exerts on the bat is

exactly 1500N whether or not the box moves

A puck sliding on a frictionless surface undergoes a change in momentum due to a constant force, which of the following expression could be used to determine the change in momentum? (F(delta d); f*t; F(delta v); F(delta v / delta t)

f*t

Two friends are standing on opposite ends of a canoe that is initially at rest with respect to a frictionless lake. The person in the front throws a very massive ball toward the back, and the person in the back catches it. After the ball is caught, the canoe is

stationary

You slam on the brakes of your car in a panic, and skid a certain distance on a straight, level road. If you had been traveling twice as fast, what distance would the car have skidded, under the same conditions?

it would have skidded 4 times farther

What is the unit for angular momentum?

kg m^2/s

What is an SI base unit (gram, slug, newton, centimeter, or kilogram)

kilogram

If an object travels at a constant speed in a circular path, the acceleration of the object is

larger in magnitude if the radius of the circle is smaller

The padding on car dashboards does what to improve safety?

lengthens the time of a passenger's impact during a collision

Which is not a vector quantity? (mass, velocity, acceleration, displacement)

mass

A ball drops some distance and gains 30 J of kinetic energy. Do not ignore air resistance. How much gravitational potential energy did the ball lose? (more than, equal to, or less than

more than 30 J

An object that has kinetic energy must be

moving

work is done when

neither force nor displacement are zero

Two men, Joel and Jerry, push against a solid brick wall. Jerry stops after 10 min, while Joel is able to push for 5.0 min longer. Compare the work they do.

neither of them does any work

Supposed you are playing hockey on a new age ice surface for which there is no friction between the ice and the hockey puck. You wind up and hit the puck as hard as you can. After the puck loses contact with your stick, the puck will

not slow down or speed up

Two gliders of the same mass are on an air track. One collides inelastically with the other one, initially at rest. What will the final velocity of the two gliders be?

one half the original velocity

a pilot drops a package from a plane flying horizontally at a constant speed. Neglecting air resistance when the package hits ground the horizontal location of the plane will be

over the package

The pulley-system consists of two solid discs of different radii fastened together coaxially, with two different masses connected to the pulleys. Under what condition will the pulley be in equilibrium (r is connected to M and R is connected to m)

rM=Rm

which of the following would not be considered projectile (a cannonball: thrown, rolling, thrown up, rolled off a table)

rolling

You are in a train traveling on a horizontal track and notice that a piece of luggage starts to slide directly toward the front of the train. From this observation, you can conclude that this train is

slowing down

If you toss a ball upward with a certain initial speed, it reaches a maximum height h. By what factor must you increase the initial speed of the ball for it to reach a maximum height 3h?

square root 3

The force exerted by any segment of a string or rope on an adjoining segment is...?

tension

A batter strikes a baseball with a bat. Identify an action-reaction pair and describe the forces exerted by each.(between batter and bat)

the batter exerts a force on the bat; the bat exerts a force on the batter

A child with a mass of 23kg rides a bike with a mass of 5.5kg at a velocity of 4.5m/s to the south. Compare the momentum of the child with the momentum of the bike.

the child has a greater momentum than the bike

The current definition of the standard meter of length is based on

the distance traveled by light in a vacuum

When a parachutist jumps from an airplane, he eventually reaches a constant speed, called the terminal velocity. This means that

the force of air drag on him is equal to his weight

An apple falls straight down from a tree. As it falls, (gravitational force pos or neg and gravitational potential energy increase or decrease)

the gravitational force does positive work on it and the gravitational potential energy decreases

Two objects, one of mass m and the other of mass 2m, are dropped from the top of a building. When they hit the ground

the heavier one will have twice the kinetic energy of the lighter one

While an object is in projectile motion (with upward being positive) with no air resistance

the horizontal component of its velocity remains constant and its vertical component of its acceleration is equal to -g

Complete the following statement: The term net force most accuratley describes

the quantity that changes the velocity of an object

a spring-loaded gun is aimed horizontally and is used to launch identical balls with different initial speeds. The gun is at a 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 ball fired, how is the horizontal range affected?

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

A rocket explodes into two fragments, one 25 times heavier than the other. the magnitude of the momentum of the lighter fragment is

the same as the momentum of the heavier fragment

Alice and Tome dive from an overhang into the lake below. Tom simply drops straight down from the edge, but Alice takes a running start and jumps with an initial horizontal velocity of 25 m/s. Neither person experiences any air resistance. Compare the time it takes each of them to reach the lake below

they reach the surface at the same time

Units of power include which of the following? (watt, horse power, kilowatt-hour, joule)

watt and horse power

If there is some physical quanitity "w" what would expression be for delta w

wf-wi

A moving freight car runs into an identical car going the opposite direction at the same speed. The cars stick together. Compared to the velocity of the first car before the collision, the velocity of the combined cars after the collision is:

zero

A stalled car is being pushed up a hill at a constant velocity by three people. the net force on the car is

zero

a tractor driving at a constant speed pulls a sled loaded with firewood. there is friction between the sled and the road. The net work done on the sled after it has moved a distance d is...

zero

After a cannonball is fired into frictionless space, the amount of force needed to keep it going equals

zero, since no force is necessary to keep it moving