PHYS 1310 Mount FINAL REVIEW

The force of friction on a sliding object is 10 N. The applied force needed to maintain a constant velocity is

10 N

a 1 kg rock that weighs 10 N is thrown straight upward at 20 m/s. Neglecting air resistance, the net force that acts on it when it is half way to the top of its path is

10 N

a block pulled to the left with 15 N and to the right with 5 N at the same time experiences a net force of

10 N

if you throw a ball straight downward (in the absence of air resistance), after leaving your hand its acceleration is

10 m/s/s

when a ball thrown straight upwards reaches the very top of its path, its acceleration is

10 m/s/s

The mass of a lamb that weighs 110 N is about

11 kg

A jumbo jet has a mass of 100,000 kg. The thrust for each of its four engines is 50,000 N. What is the jet's acceleration when taking off?

2 m/s/s

while an airplane flies at 40 m/s at an altitude of 500 meters, the pilot drops a heavy package that falls to the ground. neglecting air drag, about where does the package land relative to the plane flying above?

directly beneath the plane

in order to quadruple an objects KE, we must

double its speed

two objects move toward each other due to gravity. as the objects get closer and closer the force between them

increases

the moons acceleration is directed

inward, toward the center of the earth

If the net force on a cart is tripled, the cart's acceleration

is three times as much

A skydiver steps from a helicopter and falls for a few seconds until terminal velocity is reached. Thereafter, until he opens his parachute, his acceleration

is zero

"energy" could be best defined as

the capacity to do work

a car is rounding the top, or crest, of a hill while moving at a steady 50 km/hr. what can you say about the cars acceleration and why

the car is accelerated because its direction of motion is changing

it is correct to say that the impulse is equal to

the change in momentum it produces

what does the word "normal" mean in the phrase "normal force"

the component of the force exerted by a surface perpendicular to the surface

Suppose that an object travels from one point in space to another. Make a comparison between the displacement and the distance traveled

the displacement is either less that or equal to the distance traveled

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

the force of air resistance is equal to the weight of the parachutist

a solid cylinder and a hollow cylinder have the same mass and the same radius. which statement is true concerning their moment of inertia about an axis through the exact center of the flat surfaces?

the hollow cylinder has the greater moment of inertia

A sheet of paper can be withdrawn from under a container of milk without toppling it if the paper is jerked quickly. This best demonstrates that

the milk carton has inertia

a ball is rolling along the floor. it is rolling toward the east, and slowing down as it rolls. as the ball rolls,

the net force on it is towards the west

A bowling ball and a baseball accelerate equally when falling in a vacuum because

the ratio of their weights to mass is the same

for a system in mechanical equilibrium

the resultant forces and torques must both be zero

Dr. Chuck projects a ball horizontally from a lab bench. The ball lands on a bullseye marked on the floor a horizontal distance away. Compared to the time for the ball to simply drop vertically from the bench, the time in the air for the ball is

the same

an automobile and a golf cart traveling at the same speed collide head-on. The impact force is

the same for both

James and John dive from an overhang into the lake below. James simply drops straight down from the edge. John takes a running start and jumps with an initial horizontal velocity of 25 m/s. When they reach the lake below,

the splashdown speed of John is larger than that of James

it's harder to stop or turn a moving supertanker than a small speedboat because

the supertanker has a larger momentum

Two objects have masses m and 5m, respectively. they are both placed side by side on a frictionless inclined plane and allowed to slide down from rest

the two objects reach the bottom of the inclined plane at the same time

Nellie tosses a ball upward at an angle. Assuming no air resistance, which component of velocity changes with time?

the vertical component

A runner runs around a track cosseting of two parallel lines 96 m long connected at the ends by two semicircles with a radius of 49 m. She completes one lap in 100 seconds. What is her average velocity?

0 m/s

a car weighing 5000 N is traveling along a straight level road powered by a forward drive force of 500 N. The force of air resistance is 200 N, and the rolling resistance is 100 N. The net force on the car is

200 N

a car has a mass of 1000 kg and accelerates at 2 m/s/s. what net force is exerted on the car

2000 N

suppose you slowly, and at a constant speed, lift a book weighing 12 N from the floor to a shelf 2 m above the floor. neglect air resistance. the work done by you on the book is

24 J

how much kinetic energy does a .30 kg stone have if it is thrown at 44 m/s

290 J

when a karate chop breaks a board with a 3000 N blow, the amount of force that acts on the hand is

3000 N

a force of 120 N is applied to an object whose mass is 30 kg. The object's acceleration is...

4.0 m/s/s

For which value of theta is the range of a projectile fired from ground level maximum?

45 degrees above the horizontal

A person has a mass of 45 kg. How much does she weigh?

450 N

Forces of 8 N and 3 N act on an object. If the two forces act in opposite directions, the net force on the object is

5 N

a 2000 N car travel 50 m along a level road, powered by a drive force of 1000 N. The work done by the drive force is

50,000 J

a 10 N falling object encounters 4 N of air resistance. The net force on the object is

6 N

a person has a mass of 45 kg. how much does she weigh on the Moon, where g=1.62 m/s/s

73 N

how much work would a child do while pulling a 12 kg wagon a distance of 4.3 m with a 22 N force

95 J

The acceleration of an object doesn't have to be in the same direction as the net force applied to it (T/F)

False

The mass of the Moon is about 1/80 of the mass of Earth. The force exerted by Earth on the Moon is about 80 times that exerted by the Moon on the Earth

False

an acorn falls from a tree. compare its kinetic energy K, to its potential energy, PE

K increases and PE decreases

Suppose that an object travels from one point in space to another. Make a comparison between the displacement and the distance traveled.

The displacement is either less than or equal to the distance traveled

The vertical component of the acceleration of a projectile remains constant during the entire trajectory of the projectile. True/False

True

When the velocity and acceleration of an object have the same sign, the speed of the object increases. True/False

True

an object is in free fall as it is released, whether it is dropped from rest, thrown downward, or thrown upward (T/F)

True

a mack truck and a volkswagon traveling at the same speed have a head-on collision. The vehicle that undergoes the greatest change in velocity will be the

Volkswagon

A dropped ball gains speed because

a gravitational force acts on it

a dropped ball gains speed because

a gravitational force acts on it

a small car and a large truck collide head on. during the collision the little car experiences

a much larges acceleration than the truck

A vector quantity is defined as

a quantity that is specified by using a numerical value and a direction

suppose we subject a golf ball and a more massive lead ball to identical net forces. Then compared to the golf ball, the lead ball must have

a smaller acceleration

A package falls off a truck that is moving at 30 m/s. Neglecting air resistance, the horizontal speed of the package just before it hits the ground is

about 30 m/s

You would be richest if your hunk of gold had a mass of one kilogram

actually it wouldn't make a difference

an archer shoots an arrow. consider the action force to be the bowstring against the arrow. the reaction to this force is the

arrow's push against the bowstring

A truck is moving at a constant velocity. inside the storage compartment, a rock is dropped from the midpoint of the ceiling and strikes the floor below. the rock hits the floor

at exactly below the midpoint of the ceiling

a figure skater is spinning slowly with arms outstretched. she brings her arms in close to her body and her angular speed increases dramatically. the speed increase is a demonstration of

conservation of angular momentum: her moment o inertia is decreased, and so her angular speed must increase to conserve angular momentum

a constant net force acts on an object. describe the motion of the object.

constant non-zero acceleration

According to Newtonian physics, an object with no forces acting on it must

either be at rest or have constant velocity

for every action force, there must be a reaction force that is

equal in magnitude

the force with which Earth pulls on the moon is

equal in magnitude to the force that the moon pulls on earth

A ball is thrown up into the air. Ignore air resistance. When it is rising and reaches half of its max height, the net force acting on it is

equal to its weight

A person is lowering a bucket into a well with a constant speed. The force exerted by the rope on the bucket is

equal to the buckets weight

When you drop a rubber ball on the floor it bounces back. The force exerted on the ball to produce bouncing is by the

floor

to what two quantities is work proportional

force and distance

an object is released from rest a height "h" above the ground. a second object with four times the mass of the first is released from the same height. the potential energy of the second compared to the first is

four times as much

the force of earth gravity on a capsule in space increases as it comes closer. when the capsule moves to half its distance, the force toward earth is then

four times greater

the type of energy that a swinging pendulum has at the high point of its swing is

gravitational

according to newton, the greater the masses of interacting objects, the

greater the gravitational force between them

Marcia places a lead block and an iron block on the table, and hits both of them with the same force. The lead block is twice as massive as the iron block. The acceleration of the lead block is

half that of the iron block

you toss a ball to your friend. when the ball reaches its maximum altitude, its velocity is

horizontal

If you toss a coin straight upward in a train that gains speed while the coin is in the air, the coin will land

in back of you

a stone is thrown straight up. When it reaches its highest point...

its velocity is zero and its acceleration is not zero

A ball rolled along a horizontal surface maintains a constant speed because

its velocity remains constant

a one kilogram grapefruit weighs ten newtons. suppose we take this grapefruit to the moon. the force of gravity on the grapefruit will then be

less that 10 newtons

according to newton, the greater the distance between masses of interacting objects, the

less the gravitational force between them

Each of us weigh a tiny bit less inside the ground floor of a skyscraper that we do on the ground away from the skyscraper because the

mass of the building above slightly attracts us upward

one situation in which the law of conservation of energy is violated is

nonsense-no violations of this law have ever been observed

a golf club hits a golf ball with a force of 2400 N. The golf ball hits the club with a force

of 2400 N

a car by itself is capable of a certain maximum acceleration. when it tows a car of the same mass, its maximum acceleration is

one half

what physical quantity is measured in watts

power

The accelerations possible for a ball on an inclined plane

range from zero to g

For a projectile launched horizontally, the horizontal component of a projectile's velocity

remains a non-zero constant

Galileos use of the inclined plane allowed him to effectively

slow down the acceleration of free fall

A "force" could be best described as

something on body does to another body that can cause the second body to accelerate

the center of mass of a human bey is located at a point

that changes as a person bends over

to catch a ball, a baseball player extends the hand forward before impact with the ball and the lets it ride backward in the direction of the balls motion. doing this reduces the force of impact on the player's hand principally because the

time of impact is increased

Free fall is the motion of an object subject only to the influence of gravity (T/F)

true

It is possible to have a zero acceleration, and still be moving.. true/false

true

The average velocity of a car traveling with a constant acceleration during a certain time interval is equal t the mean of the velocities at the beginning and end of that time interval. True/False

true

if no force is applied to a moving object, it will continue to move with constant speed in a straight line (T/F)

true

a car travels east and its velocity decreases. the acceleration of the car is in which direction?

westward

While you are standing in the aisle of a bus, the driver suddenly makes a left turn. You lurch to the right due to

your tendency to keep moving forward

The net force acting on an insect falling downward at constant velocity is

zero

you hold a 2 newton apple, having a mass of 0.2 kg, at rest in your hand. the net force on the apple is then

zero