PHYS 100 Final

A man weighing 800 N stands at rest on two bathroom scales so that his weight is distributed evenly over both scales. The reading on each scale is A) 200 N B) 400 N C) 800 N D) 1600 N E) none of these

B) 400 N

An object is pulled northward with a force of 10 N and southward with a force of 15 N. The magnitude of the net force on the object is A) 0 N B) 5 N C) 10 N D) 15 N E) none of these

B) 5 N

TRUE OR FALSE: 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 directed downward.

TRUE

TRUE OR FALSE: A basketball player wants to balance a ball on her fingertip. It will help to spin the ball.

TRUE

TRUE OR FALSE: If you push for an hour against a stationary wall you do not do work on the wall.

TRUE

TRUE OR FALSE: It is correct to say that impulse is equal to the change in momentum.

TRUE

TRUE OR FALSE: Neglecting air resistance, the horizontal velocity of a projectile remains constant.

TRUE

TRUE OR FALSE: The Conservation of Energy states that energy cannot be created or destroyed.

TRUE

TRUE OR FALSE: The difference between impulse and impact force involves the time the force acts.

TRUE

TRUE or FALSE: 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 directed downward.

TRUE

TRUE or FALSE: A completely submerged object always displaces its own volume of fluid.

TRUE

TRUE or FALSE: A force is a vector quantity because it has both magnitude and direction.

TRUE

TRUE or FALSE: A good heat conductor is also a good insulator

TRUE

TRUE or FALSE: A hockey puck is set in motion across a frozen pond. If ice friction and air resistance are neglected, NO force is required to keep the puck sliding at constant velocity.

TRUE

TRUE or FALSE: An object CANNOT be in mechanical equilibrium with only a single force acting on it.

TRUE

TRUE or FALSE: Heat energy is measured in units of joules or calories.

TRUE

TRUE or FALSE: If a car moves with constant velocity, it also moves with constant speed.

TRUE

TRUE or FALSE: In science, an educated guess is a hypothesis.

TRUE

TRUE or FALSE: Steam burns are more damaging than burns caused by boiling water because steam gives up additional energy when it condenses.

TRUE

TRUE or FALSE: The Earth's gravitational field extends throughout the universe

TRUE

TRUE or FALSE: The scientific method includes observing a phenomenon and then formulating a hypothesis based on that observation.

TRUE

TRUE or FALSE: There are no more than about 100 different elements that are stable and combine to form all of the stable substances in the universe.

TRUE

TRUE or FALSE: Water pressure is greatest against the bottom of a submerged object.

TRUE

TRUE or FALSE: Some molecules are able to absorb large amounts of energy in the form of internal vibrations and rotations. Materials composed of such molecules have high specific heats.

TRUE?

A rock is dropped down a deep well. It takes 4 seconds to reach the bottom. How deep is the well? A) 20 m B) 40 m C) 60 m D) 80 m E) 100 m

80 meters HINT: d=5t^2

Evaporation is a cooling process and condensation is: A) a warming process B) a cooling process also C) neither a warming nor a cooling process

A) a warming process

Entropy is a measure of: A) disorder B) temperature C) order D) none of these

A) disorder

Whereas impulse involves the time a force acts, work involves the A) distance that a force acts B) the time and distance that a force acts C) the acceleration that a force produces D) all of these E) none of these

A) distance that a force acts

Which requires more work to stop -- a light truck or a heavy truck moving with the same momentum? A) the light truck requires more work to stop B) the heavy truck requires more work to stop C) both require the same work to stop D) there is not enough information to answer the question

A) the light truck requires more work to stop

A player catches a ball. Consider the action force to be the impact of the ball against the player's glove. The reaction to this force is the A) player's grip on the glove B) force the glove exerts on the ball C) muscular effort in the player's arms D) friction of the ground against the player's shoes E) none of these

B) force the glove exerts on the ball

A broom is easier to balance vertically when the heavier end (the brush end) is A) nearest your hand B) highest, farthest from your hand C) the same either way D) none of these

B) highest, farthest from your hand

Horses that move with the fastest linear speed on a merry-go round are located A) near the center B) near the outside C) anywhere, because they all move with the same speed

B) near the outside

A rifle recoils from firing a bullet. The speed of the rifle's recoil is small because the: A) force against the rifle is smaller than against the bullet B) rifle has much more mass than the bullet C) momentum is mainly concentrated in the bullet D) momentum of the rifle is smaller

B) rifle has much more mass than the bullet

A torque acting on an object tends to produce A) equilibrium B) rotation C) velocity D) a center of gravity E) linear motion

B) rotation

Newton discovered: A) gravity B) that gravity is universal C) neither

B) that gravity is universal

The reason that buoyant force acts upward on a submerged object is that: A) if it acted downward, nothing would float B) upward pressure against the bottom is greater than downward pressure against the top of the submerged object C) it acts in a direction to oppose gravity D) the weight of fluid displaced reacts with an upward force

B) upward pressure against the bottom is greater than downward pressure against the top of the submerged object

When a rock thrown straight upwards gets to the exact top of its path, its A) velocity is zero and its acceleration is zero B) velocity is zero and its acceleration is about 10 meters per second per second C) velocity is about 10 m/s and its acceleration is about 10 meters per second per second D) velocity is about 10 m/s and its acceleration is zero E) none of these

B) velocity is zero and its acceleration is about 10 meters per second per second

Power is equal to A) work times time B) work divided by time C) work times by distance D) work divided by distance E) none of these

B) work divided by time

Which of the following is not a vector quantity? A) velocity B) acceleration C) speed D) none are vector quantites E) all are vector quantities

C) speed

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) gravity tends to hold the milk carton secure B) the milk carton has no acceleration C) the milk carton has inertia D) none of these

C) the milk carton has inertia

An object covers a distance of 8 meters in the first second of travel, another 8 meters during the next second, and 8 meters again during the third second. Its acceleration in meters per second per second is approximately A) 5 B) 8 C) 24 D) 0

D) 0

At one instant an object in free fall is moving downward at 50 m/s. One second later its speed is A) 55 m/s B) 100 m/s C) 25 m/s D) 60 m/s E) 50 m/s

D) 60 m/s

The smallest particle of those listed below is A) a neutron B) an atom C) a proton D) a quark E) a molecule

D) a quark

Substances absorb heat energy by the process of A) convection B) radiation C) conduction D) all of these

D) all of these

According to Newton, doubling the distance between two interacting objects: A) multiplies by 2 the gravitational force between them B) multiplies by 4 the gravitational force between them C) divides by 2 the gravitational force between them D) divides by 4 the gravitational force between them

D) divides by 4 the gravitational force between them

A moving object has A) speed B) velocity C) energy D) momentum E) all of these

E) all of these

What prevents satellites such as the space shuttle from falling? A) gravity B) centripetal force C) centrifugal force D) low pressure E) nothing; they are continually falling as they orbit the Earth

E) nothing; they are continually falling as they orbit the Earth

TRUE OR FALSE: A 4 kg ball has a momentum of 12 kg m/s. The ball's speed is 4 m/s.

FALSE

TRUE OR FALSE: Lifting a 10 kg object 2 meters requires more work than lifting a 5 kg object 5 meters.

FALSE

TRUE OR FALSE: The change in gravitational potential energy depends on the path taken between two points.

FALSE

TRUE OR FALSE: The rotational inertia of an object is independent of the location of the axis of rotation.

FALSE

TRUE or FALSE: "The planet Mars is made of green cheese" is not a scientific hypothesis.

FALSE

TRUE or FALSE: An automobile that has a velocity towards the north CANNOT simultaneously have acceleration towards the south.

FALSE

TRUE or FALSE: If an object falls with constant acceleration, the velocity of the object must be constant also.

FALSE

TRUE or FALSE: In an electrically neutral atom, the number of protons in the nucleus equals the number of neutrons.

FALSE

TRUE or FALSE: The newton is a unit of mass

FALSE

TRUE or FALSE: When water is changed from a solid to a liquid state, the solid state both releases and absorbs energy

FALSE

TRUE or FALSE: When you touch a cold piece of ice with your finger, energy flows from the ice to your finger.

FALSE