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