EDS 1031 Final Exam

A 10-N falling object encounters 10 N of air resistance. The net force on it is ________.

0 N

A hockey puck slides across a frozen pond. If ice friction and air resistance are neglected, the force needed to keep the puck sliding at constant velocity is _____________.

0 N

Two billiard balls having the same mass roll toward each other at the same speed. What is the net momentum of the two-ball system?

0 kg•m/s

A sack of potatoes weighing 200 N falls from an airplane. As the velocity of fall increases, air resistance also increases. When air resistance equals 200 N, the sack's acceleration is __________.

0 m/s2

A 2-kg rifle is horizontally suspended by a pair of strings so that recoil can be measured. The rifle fires a 0.001-kg bullet at a speed of 200 m/s. The recoil velocity of the rifle is about _________.

0.1 m/s

Two identical freight cars roll without friction towards each other on a level track. One car rolls at 2 m/s and the other car rolls at 1 m/s. After the cars collide, they couple and roll together with a speed of

0.5 m/s

A 1-kg chunk of putty moving at 1 m/s collides and sticks to a 5-kg bowling ball initially at rest. The bowling ball and putty move with a momentum of

1 kg•m/s.

A 10-kg block is pushed across a horizontal surface with a horizontal force of 20 N against a friction force of 10 N. The acceleration of the block is ______.

1 m/s2

A push on a 1-kg brick accelerates the brick. Neglecting friction, to equally accelerate a 10-kg brick requires the force to be ___________.

10 times as much.

Escape speed from Earth is

11.2 km/s

What is the mass of a ball moving at 3 m/s with a momentum of 48 kg∙m/s

16 kg

If a power plant is 30% efficient, and the transmission system that delivers power to consumers is 60% efficient, then the overall efficiency is

18%

The average speed of a horse that gallops a distance of 10 km in time of 30 min is ____________.

20 km/h

A 3000-N bear grasping a vertical tree slides down at constant velocity. The friction force between the tree and the bear is __________.

3000 N

The conservation of momentum is most closely related to Newton's

3rd law

If you exert 6 N across a distance of 2 m in 3 s you'll deliver a power of

4 W

Two people, one twice as massive as the other, attempt a tug-of-war with 12 m of rope on frictionless ice. After a brief time, they meet. The heavier person slides a distance of _________.

4 m.

A stone is thrown horizontally from the top of a cliff. One second after leaving your hand it drops a vertical distance of

5 m

A piece of taffy slams into and sticks to another identical piece of taffy that is at rest. The momentum of the two pieces of taffy stuck together after the collision is the same as it was before the collision. Kinetic energy is a different story, for part of it turns into heat. What percentage of the kinetic energy converts into heat?

50%

When Danny Diver who weighs 500 N steps off a diving board 10 m above the water, he hits the water with kinetic energy of

5000 J

Six seconds after starting from rest, a freely falling baseball has a speed of ___________.

60 m/s

In science, a theory is _____________________________.

A synthesis of a large body of well-tested knowledge.

Technology is mainly ________.

A tool of science.

When you jump from an elevated position you usually bend your knees upon reaching the ground. By doing this, the contact time is about 10 times more than for a stiff-legged landing and the average force your body experiences is reduced by

About 10 times

You're lying on the sand on a breezy day when a pesky fly wishes to join you. The breeze is blowing at a steady 1 m/s. If the fly wishes to land on you it should hover over you while flying _________.

Against the breeze at 1 m/s

Science, art, and religion need not contradict one another because _____________.

All three operate in different domains.

A hydraulic press, like an inclined plane, is capable of increasing energy.

Always false

Which of these is a scientific hypothesis (that could be proved wrong)?

An atom is the smallest bit of matter in a material.

Which of the following involves passion, talent, and intelligence?

Art, Literature, Music, and Science

When you simultaneously drop a light tennis ball and a heavy bowling ball, they hit the floor

At the same speed

Which has the greatest mass? A.) a fluffed-up king size pillow B.) an automobile battery C.) a scrunched-up kin size pillow D.) all about the same

B.) An automobile battery

If Burl carried Paul piggy-back while standing in the middle of a scaffold, the tensions in the two supporting ropes would __________.

Be equal.

Which of the following is a scientific statement? A). Matter is filled with undetectable particles B.) There are parts of the universe that will never be found by humans C). The Moon is made of green cheese D.) None of the above

C). The moon is made of green cheese

A motor scooter undergoes acceleration when it ___________.

Changes direction, gains speed, or decreases speed.

To steadily (constantly) increase the velocity of something requires a ________________.

Constant net force

When Freddy Frog drops vertically from a tree onto a horizontally-moving skateboard, the speed of the skateboard

Decreases

When an object falls through the air, as velocity increases the net force ____________.

Decreases

Aristotle treated motion by

Dividing it into two classes

When you toss a coin straight up, it moves upward, turns around, and drops. During all this time the acceleration of the coin is _____________________.

Downward and constant.

A parachutist failing at constant velocity is in a state of ___________.

Dynamic equilibrium.

Earth pulls on the Moon. Similarly the Moon pulls on Earth, evidence that _________________.

Earth and Moon pull on each other and Earth's and Moon's pulls comprise an action-reaction pair.

If the Sun were twice as massive,

Earth's pull on the Sun would double, and the Sun's pull on the Earth would double.

Which has the greater momentum when moving?

Either a bullet or a container ship depending on the speed

The force of air impact upon the sail of a boat is greater if the air

Encounters the sail head-on

The unit kilowatt-hour is a unit of ___________.

Energy

Success in science is mainly linked to emphasis on ______.

Experiments

An Earth satellite in an elliptical orbit travels slowest when it is

Farthest from the Earth.

Whirl a rock at the end of a string and it follows a circular path. If the string breaks, the rock tends to _____________________.

Follow a straight-line path.

Science and technology are _________.

Fundamentally different from each other.

The scientific method is most effective in ________________________.

Gaining, organizing, and applying new knowledge.

The scientist first credited for discovering the concept of inertia was _______________.

Galileo

When a scientist is dishonest and reports false information, he or she ________________________.

Gets no second chance in the scientific community.

When an apple falls to the ground, momentum is transferred to the ground. The momentum absorbed by the ground is

Greater than that of the apple if the apple bounces.

According to Newton, the greater the masses of interacting objects, the

Greater the gravitational force between them.

Scientific equations in a conceptual course are mainly ____________.

Guides to thinking about the relationships between concepts.

Lifting a 100-N load with 50 N of force lifts it

Half as high

When a bus brakes to a stop its kinetic energy transforms to

Heat

Science is a body of knowledge that extends back to __________.

Humankind's beginnings

In science, an educated guess is a ______________.

Hypothesis

When the bottom string is pulled slowly in the heavy-ball-and-strings demonstration, the tension ___________________________________.

In the top string is due to your pull plus the weight of the ball.

If the radius of the Earth somehow decreased with no change in mass, your weight would

Increase

A heavy block at rest is suspended by a vertical rope. When the black is accelerated upward by the rope, the rope tension ____________.

Increases

If an object's mass is decreasing while a constant force is applied to the object, the acceleration _______________.

Increases

Two objects move toward each other due to gravity. As the objects get closer and closer, the force between them

Increases

A glance at the speedometer on your vehicle will tell you your __________________.

Instantaneous speed

Compared to a recoiling rifle, the bullet that is fired has a greater

Kinetic energy

A chunk of gold weighs 1 N on Earth. On the Moon its weight would be __________.

Less

Minimal orbit speed about Earth is about 8 km/s. Minimal orbital speed for a satellite about the Moon would be

Less than 8 km/s.

The language of science is __________.

Mathematics

In science, facts _________.

May change.

Science is concerned mainly with the __________.

Natural world.

Phil Physiker standing at the edge of a cliff throws one ball straight up and another ball straight down, both with the same speed. Neglecting air resistance, which ball hits the ground below with the greater speed?

Neither, both hit with the same speed.

According to the impulse-momentum relationship Ft = change in mv, a falling baseball hits a player with a force F. The t in the equation is the time

Of contact of the ball hitting the player

Which object has zero acceleration?

One in mechanical equilibrium, one moving at constant velocity, and one at rest

Earth exerts a force on the Moon. These two bodies make up _________________.

One interaction

A scientific hypothesis can be disproved with _________________.

One reproducible experiment.

Of the sciences known as physics, chemistry, and biology, the most basic is _____________.

Physics.

The force exerted on the tires of a car to directly accelerate the car along a road is exerted by the _______________.

Road

A car traveling at 100 km/h strikes an unfortunate bug that splatters on the windshield. The force of impact is greater on the ____________.

Same for both

The statement, "There are regions beneath the Earth's crust that will always be beyond the reach of scientific investigation," is ___________.

Speculation

The ultimate source of energy from fossil fuels is the

Sun

A truly educated person is knowledgeable about _____________.

The Arts, Religion, and Science.

A 50-kg sack is lifted 2 m in the same time as a 25-kg sack is lifted 4 m. The power expended in raising the 50-kg sack compared to the power used to lift the 25-kg sack is

The same

A force of 1 N accelerates a 1-kg mass at 1 m/s2. The acceleration of a 2-kg mass acted upon by a force of 2 N is _____________.

The same

Whether a truck comes to a stop by crashing into a haystack or a brick wall, the impulse is

The same

A ball rolling down an incline has its maximum potential energy at

The top

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

To say there is no such thing as only one force means _______________.

There must also be an oppositely directed force.

The distinction between impulse and force involves the

Time the force acts.

The emphasis of the orange-and-apple sequence in your text is _______________.

To define systems

An object lifted 10 m gains a certain amount of potential energy. If it is lifted 20 m, its gain in potential energy is

Twice as much

A moving object has

Velocity, momentum, speed, and energy

An empty jug of weight W is at rest on a table. When the water of weight w is poured into it, the amount of support force supplied by the table is __________.

W + w

Lift an object against the force of gravity if you want to judge its _____________.

Weight

When does an object have zero acceleration?

When it is at rest, in mechanical equilibrium, and when moving at a constant velocity.

Power is defined as the

Work done divided by the time to do the work.

A hypothesis that is scientific must have a test for proving it ___________.

Wrong

Earth moves about 30 km/s relative to the Sun. When you jump upward in front of a wall, the wall doesn't slam into you at 30 km/s because the wall _____________________.

and you move at the same horizontal speed, before, during, and after your jump

A melon is projected into the air with 100 J of kinetic energy in the presence of air resistance. When it returns to its initial level its kinetic energy is _____________.

less than 100 J

A quick jerk on a sheet of paper beneath a box of cereal doesn't topple the box, which best illustrates that _______________.

the box has inertia.