Physics Chapter 2

Which of the following is a vector quantity? A) Mass B) Volume C) Area D) None of the above.

None of the above.

Inertia A) Explains why things stay in motion but not why they stay at rest. B) Describes why it is easier to get a massive ball moving than it is to get a less massive one moving. C) Explains why things stay at rest but not why they stay in motion. D) The tendency of a body to maintain its state of motion in the absence of applied forces.

The tendency of a body to maintain its state of motion in the absence of applied force.

Consider Nellie hanging at rest. If the ropes were vertical, with no angle involved, what would be the tension in each rope? A) The tension in each rope would be equal to the gravity force. B) The tension would be zero in both ropes. C) The tension in each rope would be twice the gravity force. D) The tension in each rope would be half of the gravity force.

The tension in each rope would be half of the gravity force.

The force of friction on a sliding object is 10 N. The applied force needed to maintain a constant velocity is A) 10 N. B) Less than 10 N. C) More than 10 N.

10 N.

Burl and Paul have a total weight of 1300 N. The tensions in the supporting ropes that support their scaffold add to 1700 N. The weight of the scaffold itself must be A) 300 N. B) 500 N. C) 600 N. D) 400 N.

400 N.

What does it mean to say something is in mechanical equilibrium? A) An object in mechanical equilibrium experiences a zero net force. B) An object in mechanical equilibrium is always in motion. C) An object in mechanical equilibrium experiences a net force twice its weight. D) An object in mechanical equilibrium must experience no forces.

An object in mechanical equilibrium experiences a zero net force.

When a pair of 10-N forces act on a box of candy, the net force on the box is A) Zero. B) 20 N. C) About 14 N. D) Any of the above depending on the directions of forces.

Any of the above depending on the directions of forces.

When you quickly jerk a cart forward that has a ball resting in the middle, the A) Back of the cart hits the ball. B) Front of the cart hits the ball. C) Neither, for the ball rides along in the middle as the cart moves forward. D) All of the above depending on how quickly the cart is pulled.

Back of the cart hits the ball.

An elevator moves straight upward at a constant speed. Newton's first law predicts that the net force acting on the elevator will _____. A) Point upward B) Be increasing C) Be zero

Be zero

What did Galileo discover in his legendary experiment on the Leaning Tower of Pisa? A) Galileo found that a heavier stone does not fall significantly faster than a lighter one. B) Galileo found that stones fall faster proportional to their weight. C) Galileo found that air resistance significantly slowed falling stones. D) Galileo found that a heavier stone falls significantly faster than a lighter one.

Galileo found that a heavier stone does not fall significantly faster than a lighter one.

When Nellie Newton hangs by the ends of a rope draped over a large pulley, the tension in each supporting vertical strand is A) Half her weight. B) Twice her weight. C) Equal to her weight. D) None of the above

Half her weight.

According to Newton's first law, when the net force acting on an object is zero, the object must _____. A) Have zero velocity B) Be speeding up C) Have constant velocity D) Be slowing down

Have constant velocity

What was the greatest discovery by Galileo during his inclined-plane experiments? A) He discovered that balls rolling down an incline gain speed and balls rolling up an incline lose speed. B) He discovered that a ball rolling down an incline and onto a horizontal surface would roll indefinitely. C) He discovered that light and heavy objects gain the same speed when rolling on inclines. D) He discovered that heavy objects roll faster than light objects on an incline.

He discovered that a ball rolling down an incline and onto a horizontal surface would roll indefinitely.

A hockey puck sliding at constant velocity across the ice is A) In equilibrium. B) Is nowhere near being in equilibrium. C) Nearly in equilibrium. D) None of the above

In equilibrium.

What did Galileo discover about moving bodies and force in his experiments with inclined planes? A) Bodies rolling down a steep inclined plane starting at a given height rolled up a gently inclined plane to a higher height. B) Bodies rolling down an inclined plane slowed down. C) In the absence of a retarding force, a body will keep moving at a constant speed in a straight line forever. D) Bodies rolling up an inclined plane sped up.

In the absence of a retarding force, a body will keep moving at a constant speed in a straight line forever.

If your automobile runs out of fuel while driving, the engine stops. You don't come to an abrupt stop due to A) The principle of continuation. B) Gravity. C) Resistance. D) Inertia.

Inertia.

What type of path does a moving object follow in the absence of a force? A) It moves in a straight line and eventually slows to a stop. B) It continues to move in a straight line at a constant speed. C) It follows a parabolic trajectory in the absence of a force. D) It follows a circular path in the absence of a force.

It continues to move in a straight line at a constant speed.

Galileo taught us that if you roll a ball along a level surface it will A) Soon slow down due to its natural place. B) Soon roll in the opposite direction. C) Keep rolling if friction is absent. D) Roll as long as its inertia nudges it along.

Keep rolling if friction is absent.

How does Newton's first law of motion relate to Galileo's concept of inertia? A) Newton expressed Galileo's concept of inertia with the inertia equation. B) Newton's first law of motion refuted Galileo's concept of inertia. C) Newton replaced Galileo's concept of inertia with his three laws of motion. D) Newton refined Galileo's concept of inertia and made it his first law of motion.

Newton refined Galileo's concept of inertia and made it his first law of motion.

A hockey puck is set in motion across a frozen pond. If ice friction and air resistance are neglected, the force required to keep the puck sliding at constant velocity is A) Equal to its weight divided by its mass. B) Equal to its weight. C) Equal to its mass times its weight. D) None of the above.

None of the above.

A pair of wires support a heavy painting. Tension in the wires is greater when they are A) The same regardless of the wire orientation. B) Vertical. C) Not vertical. D) None of the above

Not vertical.

A hockey puck sliding across the ice finally comes to rest because A) That's just the way it is. B) Of friction. C) It seeks its proper and natural state.

Of friction.

Galileo's use of inclined planes allowed him to effectively A) Eliminate all changes in speed. B) Reduce the time of the ball's changes in speed. C) Eliminate friction. D) Slow down the ball's changes in speed.

Slow down the ball's changes in speed.

According to the parallelogram rule, what quantity is represented by the diagonal of a constructed parallelogram? A) The diagonal is the resultant, or sum, of two vectors. B) The diagonal is always 1.41 times the magnitude of the sum of the vectors. C) The diagonal is 1.41 times the magnitude of the longest vector. D) The diagonal is the difference of two vectors.

The diagonal is the resultant, or sum, of two vectors.

If you push on a crate with a horizontal force of 100 N and it slides at constant velocity, what is the magnitude and direction of the frictional force acting on the crate? A) The frictional force on the crate is 100 N opposite the direction of motion. B) The frictional force on the crate is zero newtons. C) The frictional force has nothing to do with you pushing on the crate. D) The frictional force on the crate is 100 N in the same direction as the direction of motion.

The frictional force on the crate is 100 N opposite the direction of motion.

What is the net force on a cart that is pulled to the right with 100 pounds of force and to the left with 30 pounds of force? A) The net force is zero. B) The net force is 70 pounds to the right. C) The net force is 130 pounds. D) The net force is 70 pounds to the left.

The net force is 70 pounds to the right.

What is the net force on a bag pulled down by gravity with a force of 18 newtons and pulled upward by a rope with a force of 18 newtons? A) The net force is 18 newtons. B) The net force is 36 newtons. C) The net force is 25 newtons. D) The net force is zero newtons.

The net force is zero newtons.

What is the net force on an object in either static or dynamic equilibrium? A) The net force is zero. B) The net force is vertical for static equilibrium and horizontal for dynamic equilibrium. C) The net force is zero for static equilibrium and greater than zero for dynamic equilibrium. D) The net force is equal and opposite to the weight of the object.

The net force is zero.

A bowling ball at rest is in equilibrium. Is the ball in equilibrium when it moves at constant speed in a straight-line path? A) The bowling ball is not in equilibrium because the wood of the bowling alley exerts an upward force on the ball. B) The bowling ball is not in equilibrium because ΣF = -mg. C) The bowling ball is not in equilibrium because it is moving. D) Yes, the bowling ball is in equilibrium because ΣF = 0.

Yes, the bowling ball is in equilibrium because ΣF = 0.

While you are standing in the aisle of a bus, the driver suddenly makes a left turn. You lurch to the right due to A) An equilibrium challenge. B) An unbalanced force. C) Your tendency to keep moving forward.

Your tendency to keep moving forward.

When you stand at rest on a bathroom scale, how does your weight compare with the support force from the scale? A) The support force from the scale is half your weight. B) Your weight is equal in magnitude and opposite in direction to the support force from the scale. C) The support force from the scale is twice your weight. D) Your weight is equal in magnitude and in the same direction as the support force from the scale.

Your weight is equal in magnitude and opposite in direction to the support force from the scale.

The net force on any object in equilibrium is A) Non-zero when motion is involved. B) Less than its weight. C) Equal to its weight. D) Zero.

Zero.