A scientific statement that can never be changed is a scientific
A) theory.
B) principle.
C) hypothesis.
D) law.
E) None of the above choices are correct.
E) None of the above choices are correct.
As an object falls
A) its velocity increases
B) its acceleration increases
A) its velocity increases
acceleration due to gravity is a constant
Whirl a rock at the end of a string on an ice-covered pond and it follows a circular path. If the string breaks, the tendency of the rock is to
A) travel in a straight line
B) continue in a circular pattern
A) travel in a straight line
When you yank a table cloth out from under your dishes you are demonstrating
A) impulse
B) inertia
C) gravity
D) momentum
B) inertia
What is the acceleration of a freely falling object?
A) 10 m/s^2
B) 0 m/s^2
C) 5 m/s^2
A) 10 m/s^2
A package falls out of an airplane that is traveling at 300m/s. Neglecting air resistance, what is its horizontal velocity before hitting the ground?
A) greater than 300m/s
B) equal to 300m/s
C) less than 300m/s
B) equal to 300m/s
A disco ball falls from the midpoint of the ceiling of a moving van. It lands
A) at a point in front of the midpoint
B) at a point behind the midpoint
C) directly below the midpoint
C) directly below the midpoint
If you run out of gas while driving you don't come to a sudden stop. Why?
A) inertia
B) gravity
C) weight
D) terminal velocity
A) inertia
According to Newton's laws a train in motion would continue moving with its engines off. Why don't we observe this
A) government conspiracy
B) gravity
C) friction
D) impulse
C) friction
A moving object must have a change of
A) heart
B) position
C) direction
D) momentum
B) position
If a spaceship accelerating in outer space runs out of fuel it
A) continue to accelerate
B) no longer accelerates
C) slows to a stop
B) no longer accelerates
If no external forces act on an object it will
A) continue moving with the same speed
B) continue moving with the same velocity
B) continue moving with the same velocity
The last instant just before an airplane crashes a passenger jumps out the door and falls only two feet to the ground. The passenger is
A) intelligent to think so fast
B) lucky to have studied physics
C) unharmed
D) probably hurt of killed
D) probably hurt of killed
According to Newton’s law of inertia, the result of walking much of the day is similar to tightening the head of a hammer when its handle hits a solid surface so that we are actually a little bit shorter in the
A) morning
B) Evening
C) No difference
A) morning
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
A) the milk carton has no acceleration.
B) there is an action-reaction pair of forces.
C) gravity tends to hold the milk carton secure.
D) the milk carton has inertia.
E) None of these
D) the milk carton has inertia.
According to Newton’s law of inertia, a railroad train in motion should continue going forever even if its engine is turned off. We never observe this because railroad trains
A) move too slowly.
B) are much too heavy.
C) must go up and down hills.
D) always have forces that oppose their motion
D) always have forces that oppose their motion
A girl and a boy pull in opposite directions on strings attached to each end of a spring balance. Each child exerts a force of 20N. What will the reading on the spring balance be?
A) 0 N
B) 10 N
C) 20 N
D) 40 N
C) 20 N
A person standing on a scaffold lowers an object of weight 250N by means of a rope, at constant speed. If the weight of the rope is negligible, the force that the person exerts is …
A) constant and less than 250N
B) equal to 250N
C) less than 250N and decreasing
D) greater than 250N
B) equal to 250N
A passenger not wearing a safety belt hits the windscreen of a car in a head-on collision. This is an illustration of …
A) Newton's First Law
B) Newton's Second Law
C) the Law of Conservation of Momentum
D) Newton's Universal Law of Gravitation
A) Newton's First Law
Galileo used an incline plane to effectively
A) ¬¬eliminate friction
B) increase the acceleration beyond that of free fall
C) slow down the acceleration of gravity
C) slow down the acceleration of gravity
Which is not a vector
A) speed
B) force
C) momentum
D) velocity
A) speed
An airplane flies at 100km/hr is still air. If it flies into a 10km/hr headwind, its ground speed will be
A) 1000
B) 100
C) 90
D) 110
C) 90
A car maintains a velocity of 45km/hr for 15 seconds, its acceleration is
A) 0.333m/s^2
B) 60m/s^2
C) 3m/s^2
D) 0m/s^2
D) 0m/s^2
8 seconds after falling from rest the speed of a rock is
A) impossible to determine
B) 4m/s^2
C) 80m/s
D) 320m
C) 80m/s
If an object moves at a constant acceleration, its velocity must
A) also be constant
B) change by the same amount each second
C) change by varying amounts depending on its speed
B) change by the same amount each second
A ball is tossed upward, reaches its highest point and then falls back down. Its acceleration is
A) always upward
B) upward on the way up, and downward on the way down
C) zero
D) always downward
D) always downward
At one instant a ball is falling at 40m/s, after one second it is falling at
A) 40
B) 30
C) 50
D) 60
C) 50
Each second that an object falls the distance it covers is
A) increasing
B) constant, but not 5m or 10m
C) 5m
D) 10m
A) increasing
A ball is thrown up at 35m/s, to get to the highest point takes
A) 7s
B) 125m
C) 3.5s
C) 3.5s
When a rock is thrown straight upward, at its highest point
A) its velocity is zero
B) its acceleration is zero
C) its velocity and acceleration are both zero
A) its velocity is zero
Distance is to displacement as
A) impulse is to momentum
B) speed is to velocity
C) velocity is to acceleration
D) force is to weight
B) speed is to velocity
When you look at the speedometer in a moving car, you can see the car's __________.
A)instantaneous speed
B)average speed
C)instantaneous acceleration
D)average acceleration
A) instantaneous speed
A ball is thrown straight up. At the top of its path its acceleration is __________.
A) 0 m/s to power of (2)
B) about 5 m/s to power of (2)
C) about 10 m/s to power of (2)
D) about 20 m/s to power of (2)
C) about 10 m/s to power of (2)
In the absence of air resistance, objects fall at constant __________.
A) acceleration with each successive second
B) distance with each successive second
C) speed with each successive second
D) velocity with each successive second
A) acceleration with each successive second
As an object falls freely in a vacuum, its __________.
A) velocity remains constant
B) acceleration increases
C) velocity and acceleration increase
D) acceleration remains constant
D) acceleration remains constant
A car accelerates at 2 m/s to power of (2). Assuming the car starts from rest, how much time does it need to accelerate to a speed of 30 m/s?
A) 2 seconds
B) 15 seconds
C) 30 seconds
D) 60 seconds
B) 15 seconds
When a basketball player jumps to make a shot, once the feet are off the floor, the jumper's acceleration __________.
A) depends on launch speed
B) depends on launch direction
C) can be greater than g
D) is always g
D) is always g
Suppose you take a trip that covers 240 km and takes 4 hours to make. Your average speed is __________.
A) 30 km/h
B) 60 km/h
C) 120 km/h
D) 340 km/h
B) 60 km/h
Suppose you are in a car that is going around a curve. The speedometer reads a constant 30 miles per hour. Which of the following is true?
A) Your speed is changing
B) Your velocity is constant
C) Your acceleration is changing
D) Your acceleration is constant
D) Your acceleration is constant
If you drop a feather and a coin at the same time in a vacuum tube, which will reach the bottom of the tube first?
A) The coin
B) The feather
C) Neither, there is no gravity in a vacuum
D) Neither, they will both reach the bottom at the same time
D) Neither, they will both reach the bottom at the same time
A ball is thrown upwards and caught when it comes back down. In the absence of air resistance, the speed of the ball when caught would be __________.
A) more than the speed it had when thrown upwards
B) less than the speed it had when thrown upwards
C) the same as the speed it had when thrown upwards
D) The same as its acceleration
C) the same as the speed it had when thrown upwards
An object travels 8 meters in the first second of travel, 8 meters again during the second second of travel, and 8 meters again during the third second. Its acceleration is __________.
A) 0 m/s to power of (2)
B) 4 m/s to power of (2)
C) 8 m/s to power of (2)
D) 16 m/s to power of (2)
A) 0 m/s to power of (2)
If a freely falling object were somehow equipped with a speedometer, its speed reading would increase each second by __________.
A) about 5 m/s
B) about 10 m/s
C) about 15 m/s
D) a rate that depends on its initial speed
B) about 10 m/s
Suppose a car is moving in a straight line and steadily increases its speed. It moves from 35 km/h to 40 km/h the first second and from 40 km/h to 45 km/h the next second. What is the car's acceleration?
A) 5 km/h s
B) 10 km/h s
C) 35 km/h s
D) 40 km/h s
A) 5 km/h s
A ball is thrown straight up with an initial speed of 10 m/s. At the top of its path its instantaneous speed is __________.
A) 0 m/s
B) 5 m/s
C) 10 m/s
D) 20 m/s
A) 0 m/s
A ball tossed vertically upward rises, reaches its highest point, and then falls back to its starting point. During this time the acceleration of the ball is always __________.
A) in the direction of motion
B) opposite its velocity
C) directed upward
D) directed downward
D) directed downward
True or False
Average speed can be defined as the total time it takes for a trip divided by the total distance.
False
Average speed can be defined as the total distance of a trip divided by the total time it takes for a trip
True or False
As a ball falls freely, the acceleration each second is the same as the acceleration the second before or the second after.
True
True or False
The rate at which velocity or direction changes during a time interval time is called acceleration.
True
True or False
Acceleration means only that something is changing its speed.
False
Acceleration means that something is changing its speed or its direction or both
True or False
Velocity and speed are not exactly the same thing because, while both tell how fast something is going, velocity also tells you the direction.
True
True or False
A p-t graph of constant velocity has a line with an infinite number of slopes.
False
A p-t graph of “acceleration” has a line with an infinite number of slopes
True or False
The slope of the line on a p-t graph tells you velocity, and the slope of the line on a v-t graph tells you acceleration.
True
True or False
A ball is thrown into the air. At the highest point both the velocity and the acceleration are zero.
False
A ball is thrown into the air; at the highest point the velocity is zero but the acceleration is still 9.8 m/s2
True or False
The SI unit of velocity is the meter-second
False
The SI unit for velocity is the m/s or the km/h
True or False
When a car rounds a corner at a constant velocity, its acceleration is zero.
False
When a car rounds a corner at a constant velocity, its acceleration is not zero because the car is changing direction.
Why does time enter twice the SI unit for acceleration?
Time enters twice in the SI unit for acceleration because it is used once for the time it takes to change position and again for the time it takes to change velocity
Explain how it is possible to accelerate without changing speed.
Since acceleration means that an object is either changing speed or changing direction it is possible to accelerate without changing speed by simply changing direction.
If the line on a p-t graph is curved, what is the object doing? How would this same kind of motion look on a v-t graph? Sketch both graphs and label everything.
If the line on a p-t graph is curved, the object is accelerating. On a v-t graph this would look like a diagonal line moving up and to the right. Here is a sketch of what the graph should look like:
What is the acceleration of a car that goes from rest to 90 km/h in 6.0 seconds?
a = ? km/h
vi = 0 km/h
vf = 90 km/h
t = 6.0 s
a = vf - vi / t
a = 90 km/h - 0 km/h / 6.0 s
a = 90 km/hr / 6.0 s
a = 15 km/hdotmaths
If you drop a stone down a deep well and 3.7 seconds later you hear it splash in the water how deep must the well be? (Ignore the time it takes for the sound to travel up the well.
t = 3.7 s
a = 10 m/s^2
d = ? m
d = 1/2 at^2
d = 1/2 10 m/s2 (3.7s)2
d = 5m/s2 x 13.69 s2
d = 68.45 m
What is the velocity of a cheetah that runs 130 m in 8.0 s?+
d = 130 m
t = 8.0 s
v = ? m/s
v = d/t
v = 130 m/8.0 s
v = 16.25 m/s
Which has the greater mass?
A) an automobile battery
B) a king-size pillow
C) neither - both have the same
D) Correct: Your answer is correct.
A) an automobile battery
A kilogram is a measure of an object's
A) mass
B) weight
C) force
D) size
A) mass
Your weight is
A) equal to your mass
B) the gravitational attraction force between you and the Earth
C) a property of mechanical equilibrium
B) the gravitational attraction force between you and the Earth
Compared to the mass of a certain object on Earth, the mass of the same object on the moon is
A) zero
B) the same
C) six times as much
D) one sixth as much
B) the same
A force is a vector quantity because it has both
A) mass and acceleration
B) action and reaction counterparts
C) magnitude and direction
C)magnitude and direction
If an object's mass is decreasing while a constant force is applied to the object, the acceleration
A) decreases
B) stays the same
C) increases
C) increases
A 10-N falling object encounters 4 N of air resistance. The net force on the object is
A) 10N
B) 14N
C) 6N
D) 40N
C) 6N
A heavy block at rest is suspended by a vertical rope. When the block is accelerated upward by the rope, the rope tension
A) increases
B) stays the same
C) decreases
A) increases
A girl pulls on a 10-kg wagon with a constant horizontal force of 30 N. If there are no other horizontal forces, what is the wagon's acceleration in meters per second per second?
A) 0.3
B) 3
C) 300
D) 0
B) 3
When a falling object has reached its terminal velocity, its acceleration is
A) zero
B) upward
D) g
A) zero
A ball is thrown vertically into the air. Because of air resistance, its speed when it returns to its starting level compared with its initial speed is
A) the same
B) more
C) less
C) less
A skydiver's terminal velocity will be greatest if she falls
A) flat on her stomach
B) head first
C) with her parachute open
B) head first
Wherever there is an action force, there must be a reaction force which
A) always acts in the same direction
B) is slightly larger in amplitude than the action force
C) is exactly equal in magnitude
C) is exactly equal in magnitude
A player hits a ball with a bat. The action force is the impact of the bat against the ball. The reaction to this force is the
A) air resistance on the ball
B) force that the ball exerts on the bat
C) grip of the player's hand against the ball
D) weight of the ball
B) force that the ball exerts on the bat
The attraction of a person's body toward the Earth is called weight. The reaction to this force is
A) the Earth's surface pushing against the person's body
B) the person's body pulling on the Earth
B) the person's body pulling on the Earth
The Earth pulls on the moon. Similarly the moon pulls on the Earth, evidence that
A) the moon is smaller so its pull is smaller
B) these two pulls comprise an action-reaction pair
C) larger objects pull harder
B) these two pulls comprise an action-reaction pair
A automobile and a baby carriage traveling at the same speed collide head-on. The impact force is
A) the same for both
B) greater on the automobile
C) greater on the baby carriage
A) the same for both
A Mack truck and a Volkswagen have a head-on collision. The vehicle that undergoes the greatest change in velocity will be the
A) Volkswagen
B) same for both
C) Mack truck
A) Volkswagen
Joe pushes Bill, who is asleep. Bill
A) pushes Joe equally hard even without waking up
B) does not push even after he wakes up
C) pushes Joe immediately, but not as hard
D) will inevitably push Joe when he wakes
A) pushes Joe equally hard even without waking up
A horse exerts 500 N of force on a heavy wagon. The wagon pulls back on the horse with an equal force. The wagon still accelerates because
A) the wagon is not alive
B) the horse pulls on the wagon a brief time before the wagon reacts
C) the wagon does not accelerate because these forces are equal and opposite
D) there is a net force on the wagon
E) these forces are not an action-reaction pair
D) there is a net force on the wagon
A karate chop delivers a blow of 3000 N to a board that breaks. The force that acts on the hand during this event is
A) 3000N
B) zero
C) 6000N
D) 1500N
A) 3000N
A piece of rope is pulled by two people in a tug-of-war. Each pulls with 400 N of force. What is the tension in the rope?
A) 800N
B) zero
C) 600N
D) 400N
D) 400N
Two people, one twice as massive as the other, attempt a tug-of- war with 12 meters of massless rope on frictionless ice. After a brief time, they meet. The heavier person slides a distance of
A) 3m
B) 6m
C) 8m
D) 4m
D) 4m
A 40kg vehicle is traveling in outer space at a speed of 30 m/s . It can be stopped by applying a constant force of 200 N for
A) 24s
B) 180m
C) 15m/s
D) 6s
D) 6s