PHYS1020 Final Review
A ball is thrown horizontally from the top of a tall cliff. One second later, the ball has fallen a vertical distance of
5 m.
Which has lgreater kinetic energy, a car traveling at 30 km/h or a car of half that mass traveling at 60 km/h?
the 60-km/h car
A 1-kg chunk of putty moving at 5 m/s collides and sticks to a 5-kg bowling ball initially at negative 1 m/s . The bowling ball and putty then have a momentum of
0 kg m/s.
Starting from rest, the distance a freely falling object will fall in 10 s is about
500 m.
The weight of 6 kg of salami is about
60 N.
Disregarding air resistance, objects fall at constant
acceleration.
Density is the ratio of
mass to volume
Compared with the mass of a certain object on the Moon, the mass of the same object on the Earth is
the same
The force required to support an object in a gravitational field, is equal to
the weight of the object.
A liter is a measure of an object's
volume.
A scientific hypothesis may turn out to be right or it may turn out to be wrong. If it is a valid hypothesis, there must be a test for proving it
wrong.
The average speed of a horse that gallops a distance of 10 km in a time of 20 min is
30 km/h.
An object is placed 100 m from the Moon. The object will fall toward the
Moon.
In science, a theory is
a synthesis of a large body of well-tested knowledge.
A force is a pair because it has both
action and reaction counterparts.
A feather and a coin dropped in a vacuum fall with equal
all of the these, except kinetic energies
A truly educated person is knowledgeable about
all of these
When a rifle is fired, it recoils so both the bullet and rifle are set in motion. The rifle and bullet ideally acquire
all of these
Padded dashboards in cars are safer in an accident than non-padded ones because an occupant hitting the dash has
both increased time of impact and decreased impact force
Earth's gravitational field
does not cancel inside Earth.
Most natural phenomena we wonder about
involve several scientific disciplines.
A ball is thrown upward and caught when it comes back down. Applying air resistance, the speed with which it is caught is
less than the speed it had when thrown upward.
Which requires more work: lifting a 50-kg sack vertically 2 m or lifting a 25-kg sack vertically 5 m?
lifting the 25-kg sack
When you are in the way of a fast-moving object and can't get out of its way, you will suffer a lessor force of impact if you decrease its momentum over a
long time.
In science, facts
may change.
An object that has kinetic energy must be
moving.
The statement, "There are regions beneath Earth's crust that will always be beyond the reach of scientific investigation," is a
speculation.
The reason the Moon pulls on the Earth, is that
the Moon has mass.
The attraction of a person's body toward Earth is called weight. The other way of describing this force is
the pulling of a person's body towards Earth.
As an object freely falls, its
velocity increases
Which of the following normally warms up slower when heat is applied?
water
The power expended when a 100 N barbell is raised 2.0 m in 2 s is
100 W.
A Mack truck and a Volkswagen traveling at the same speed have a head-on collision. The vehicle to undergo the least change in velocity will be the
Mack truck.
The scientist to first introduce the concept of mathematical models was
Newton
A car has a mass of 1000 kg and accelerates at 1 m/s2. What is the magnitude of the force exerted on the car?
1000 N
A car traveling at 22 m/s comes to an abrupt halt in 0.2 s when it hits a tree. What is the deceleration in meters per second squared of the car?
110
If a projectile is fired straight up at a speed of 20 m/s, the time it takes to reach the top of its path is about
2 s
When you stand at rest on a pair of bathroom scales, the readings on the scales will always
add to your weight.
Science, art, and religion do not contradict one another because
all three have different domains.
If an object's mass is increasing while a constant force is applied to the object, the acceleration
decreases.
If a car increases its velocity from zero to 60 km/h in 5 s, its acceleration is
12 km/h s
Which of the following involves passion, talent, and intelligence?
all of these
A hockey puck is set in motion across a frozen pond. If ice friction and air resistance are included, the force required to keep the puck sliding at constant velocity is
very small
If you exert 450 J in 50 s, your power output is
9 W.
Using science to analyze nature
adds depth to our understanding and therefore adds to our appreciation of nature.adds depth to our understanding and therefore adds to our appreciation of nature.
If the mass of Earth somehow decreased with no change in radius, your weight would
decrease.
A rocket accelerates as it travels because
of its applied thrust.
Tangential velocity is velocity
perpendicular to the radius of the Earth.
Science and technology are
related to one another, but not the same thing
The synthesis of a large collection of information that contains well-tested and verified hypotheses about certain aspects of the world is known as a scientific
theory.
If a rocket initially at rest accelerates at a rate of 25 m/s2 for 1 min, its speed will be
1500 m/s.
A stone is thrown horizontally from the top of a cliff. Two seconds after it has left your hand its vertical distance below the cliff is
20 m.
A pot falls from a ledge and hits the ground two seconds later. The speed with which it hits the ground is about
20 m/s.
A job is done slowly, while an identical job is done quickly. The job done quickly, requires more ____
power.
A 10-N falling object encounters 6 N of air resistance. The magnitude of the net force on the object is
4 N.
A ball is moving at 12 m/s and has a momentum of 48 kg m/s. What is the ball's mass?
4 kg
A rifle of mass 1 kg is suspended by strings. The rifle fires a bullet of mass 1/100 kg at a speed of 400 m/s. The recoil velocity of the rifle is about
4 m/s.
Each of us weighs a tiny bit less in a tunnel. The reason for this is the
the mass of the Earth above the tunnel.
Two objects move apart from each other in space. As they move apart from each other, their velocities
decrease.
Compared with the force that brings a small car to a stop, the force required to bring a heavy truck to a stop in the same time
is more.
According to Newton, the lessor the distance between masses of interacting objects, the
more the gravitational force between them.
Scientists repeat experimental findings in order to
neither improve upon experimental design nor eliminate unseen errors
A freight train rolls along a track with considerable momentum. If it has three times as much mass, and three times as much speed, its momentum is
nine times as much.
When a car rolls to a stop at the top of a hill, its kinetic energy is transformed to
potential energy.
The scientific method is a method for
gaining new knowledge.
The two measurements necessary for calculating velocity are
distance and time.
When you touch a hot surface with your finger, energy flows
from the surface to your finger.
A light object is dropped a second earlier, than a heavier object is dropped. The heavier object reaches the ground 10 m below
later than the lighter object.
Twenty seconds after starting from rest, a freely falling object on Earth will have a speed of about
200 m/s
Which has the least mass?
a king-size pillow
Suppose a gun were made of very heavy material. Suppose also that the pellet has almost no mass. For such a weapon
the recoil force would be lessened.
When a scientist is dishonest and reports false information, he or she
gets no second chance in the scientific community.
Whenever the net force on an object is zero, its acceleration
is zero.
Which of the following is a scientific hypothesis?
The Moon is made of green cheese.
An object travels 4 m in the 1st second of travel, 4 m again during the 2nd second of travel, and 4 m again during the 3rd second. Its acceleration is therefore
0 m/s2.
A bullet fired horizontally hits the ground in 0.5 s. If it had been fired with half the speed in the same direction, it would have hit the ground in
0.5 s.
A 30-kg girl and a 60-kg boy face each other on friction-free roller blades. The girl pushes the boy, who moves away at a speed of 1.0 m/s. The girl's speed is
2.0 m/s.
If a projectile is fired straight up at a speed of 20 m/s, the total time to return to its starting position is about
4 s.
The muzzle velocity of a certain gun is 100 m/s. Neglecting air resistance, at the end of 1 s a bullet fired straight up into the air will have traveled a distance of about
95 m.
The planet Jupiter is about 300 times as massive as Earth, yet on its surface you would weigh only about three times as much. This is because
Jupiter has about ten times Earth's radius.
The conservation of momentum is not related to
Newton's Fourth Law.
A rock thrown straight upward gets to the exact top of its path. A secod later, its velocity is
about 10 m/s and its acceleration is about 10 m/s2.
A package falls off a truck that is moving at 40 m/s. Neglecting air resistance, the horizontal speed of the package just before it hits the ground is
about 40 m/s.
In a scientific experiment, a control is
both a test that duplicates an experimental test except for one variable and a way to study the effects of just one experimental variable
What prevents satellites such as the space shuttle from falling?
centrifugal force
Before a falling object has reached its terminal velocity, its acceleration is
constant.
Whirl a rock at the end of a string and it follows a circular path. If the string breaks, the tendency of the rock is not to
continue to follow a circular path.
If the radius of Earth somehow increased with no change in mass, your weight would
decrease.
Your weight is
dependant on your mass
Newton did not discover
gravity.
Science is a body of knowledge that goes back to
humankind's beginnings.
In science, an educated guess is a
hypothesis
In science, an educated guess is called a
hypothesis.
Roll a bowling ball off the edge of a table. As it falls, its vertical component of motion
increases.
In each second of fall, the distance a freely falling object will fall is
increasing.
Aristotle relied on _______ in explaining nature.
logic
Of the sciences known as physics, chemistry, and biology, the most basic is
physics.
If experimental findings are not reproducible,
the results are not considered valid.
A ball is thrown vertically into the air. Neglecting air resistance, its speed when it returns to its starting level compared to its initial speed is
the same.
A ball is thrown vertically into the air. Neglecting air resistance, its time coming down compared to its time going up is
the same.
