Conceptual Physics Homework 1

The windshield of your car traveling at 100 km/hr strikes a hapless bug with a force that spatters it. The force of impact is greater on the "Bug" "...is the same on each" "Windshield"

"...is the same on each"

The net force on a 1-N apple held above your head is "9.8 N" "1 N" "0 N"

"0 N"

A sack of potatoes that weighs 200 N falls from an airplane. as the velocity of fall increases, the air resistance also increases. When air resistance equals 200 N, the acceleration of the sack will be "0 meters per second squared" "Infinite" "9.8 meters per second squared" "4.9 meters per second squared"

"0 meters per second squared"

A ball is thrown 125 meters up into the air and then falls back to Earth. Its total time in the air is about "More than 20 seconds" "15 seconds" "5 seconds" "10 seconds"

"10 seconds"

On a planet where the acceleration of free fall is 20 meters per second squared, an object freely falling from a rest position will in 5 seconds have a speed of "5 m/s" "50 m/s" "100 m/s" "10 m/s" "20 m/s"

"100 m/s"

If a body is dropped and freely falls to the ground below, its acceleration is 1 g. If it is instead thrown at an angle upward to follow a parabolic path its acceleration is Zero Greater than zero but less than g 1 g More than 1 g

"1g

If a freely-falling body were somehow equipped with a speed- ometer on a planet where the acceleration due to gravity were 20 meters per second squared, then its speed reading each second would increase by "10 m/s" "20 m/s" "Depends on its ititial speed"

"20 m/s"

A car and occupant traveling at 80 km/hr (22 m/s) hits a tree and comes to a stop. if the time to come to a stop is 0.1Seconds the deceleration that the occupant under- goes is about "110 meters per second squared" "800 meters per second squared" "220 meters per second squared" "None of the other answers is correct"

"220 meters per second squared"

A person is attracted towards the center of the Earth by a gravitational force of 500 n. The force which the Earth is attracted towards the person is "Billions and billions of tons" "500 N" "Infinitesimally small"

"500 N"

A plant pot falls from a ledge and hits the ground 180 meters below. The speed with which it hits the ground is about "60 m/s" "120 m/s" "180 m/s" "More than 200 m/s"

"60 m/s"

An object is in free fall. At one instant, it is traveling at a speed of 50 meters per second. Exactly one second later, its speed is about "50 m/s" "32 m/s" "60 m/s" "100 m/s" "88 m/s"

"60 m/s"

The force of gravity on a 700-newton man standing on the Earth's surface is "700 N" "709.8 N" "9.8 N" "350 N"

"700 N"

When an object falls through the air, its velocity increases and its acceleration "Decreases" "Increases" "Remains the same whether in air or not"

"Decreases"

Our weight depends on the gravitational influence of the "Earth" "All of the other answers are correct" "Moon" "Sun"

"Earth"

An elephant and a feather fall through the air. The force of air resistance is actually greater on the "...is the same on each" "Feather" "Elephant"

"Elephant"

A baseball bat hits a ball with a force of 1000 n. The bat slows down because the ball exerts a resisting force against the bat of "Exactly 1000 N" "More than 1000 N" "Much less than 1000 N"

"Exactly 1000 N"

Newton's second law states that "Force is proportional to mass divided by acceleration." "Force is inversely proportional to the distance squared." "Force is proportional to mass multiplied by acceleration" "Force depends on acceleration but not on mass."

"Force is proportional to mass multiplied by acceleration"

Two objects having the same size but unequal weights are dropped through the air from a tall tower. The object to strike the ground first will be the "Lighter object" "Heavier object" "...both will strike the ground together"

"Heavier object"

The tendency of a body to maintain its state of motion is called "Acceleration" "Inertia" "Mass" "Speed" "Momentum"

"Inertia"

A bullet is dropped into a river from a very high bridge; at the same time, another bullet is fired from a gun, straight down towards the water. Neglecting air resistance, the acceleration just before striking the water "Is the same for each bullet" "Is greater for the dropped bullet" "Is greater for the fired bullet" "Cannot be determined in any way"

"Is the same for each bullet"

The discovery that the planets move in elliptical orbits with the Sun at one focus was made by "Tycho Brahe." "Halley." "Galileo." "Kepler." "Giordano Bruno."

"Kepler."

A person on the surface of the Earth has a mass of 50 kilograms and a weight of 490 newtons. If she is instead floating freely inside a space habitat far away from Earth her weight will be "Less but her mass the same" "More and her mass less" "Less and her mass more"

"Less but her mass the same"

A ball is thrown vertically into the air. Because of the effects of air resistance, compared to the speed with which it was thrown upward, its speed when it returns to starting position will be "Less" "More" "The same"

"Less"

Which of the following planets move fastest in its orbit? "Earth" "Neptune" "Mars" "Venus" "Mercury"

"Mercury"

If the mass of the Earth were increased, your weight would increase. If instead the mass of the Sun increased, your weight would "Decrease" "Not change" "Increase"

"Not change"

If the Earth were closer to the Sun, its period of revolution about the Sun would be "The same." "Shorter." "Longer." "Impossible to determine." "None of the other answers is correct

"Shorter."

If we push on a body and it does not move, then we can infer based on Newton's second law "Its inertia is greater than our push" "That something else is pushing on it also" "Three of the other answers are correct" "None of the other answers is correct" "That it is pushing back on us"

"That something else is pushing on it also"

A ball is dropped. According to Newton's third law, the action force is the Earth pulling on the ball, and the reaction is "The ball pulling on the Earth" "Non-existent in this case" "Air resistance acting against the ball" "Acceleration of the ball"

"The ball pulling on the Earth"

Which man made accurate observations of stars and planets over several years but rejected the heliocentric world system. "Copernicus" "Kepler" "Newton" "Tycho Brahe" "Galileo"

"Tycho Brahe"

The mass of a pet dog that weighs 100 N is about "1 kg" "100 kg" "10 kg" "1000 kg"

10 kg

A bag of groceries has a mass of 10 kilograms and a weight of about "10 N" "1000 N" "1 N" "100 N"

100 N

The deceleration of an automobile in a full skid on dry pavement is about 1/2 g. If you are driving at 80 km/hr (22 m/s) and slam on your brakes, the time required to skid to a stop is about 4 1/2 seconds 4 seconds 5 1/2 seconds 5 seconds

4 1/2 seconds

When two people, one twice as massive as the other, attempt a tug-of-war with a 12-meter rope on frictionless ice, they meet. The heavier person will have slid a distance of 3 meters 4 meters Can't say with the information given 6 meters

4 meters

A 10-kilogram block is set sliding with an initial velocity of 10 m/s and slides 10 meters across a horizontal surface in 2 seconds whereupon it comes to rest. The friction force acting on the block must have been about "10 N" "25 N" "5 N" "50 N"

50 N

A skydiver who weighs 500 N reaches a terminal velocity of about 90 kilometers per hour. The air resistance she encounters in fall is 250 N 90 N 500 N 410 N

500 N

How deep is a mine shaft if it takes 6 seconds for a stone to fall to the bottom? More than 200 meters About 120 meters About 180 meters About 60 meters

About 180 meters

Disregarding air resistance, falling objects fall at constant "Acceleration" "Speed" "Velocity" "Distances of 4.9 m each successive second" "All of the other answers are correct"

Acceleration

The rate of change of the velocity of a body with time is called the body's Applied force. Mass. Acceleration. Momentum. Kinetic energy.

Acceleration.

With one of the first telescopes, Galileo discovered "All of the other answers." "The four brightest moons of Jupiter." "The mountains of the Moon." "Sunspots." "That the milky way is made up of individual stars."

All of the other answers.

Whenever the net force acting on an object of constant mass is doubled, then the acceleration is "Now and then doubled" "Sort of doubled" "Most of the time doubled" "Once in a while doubled" "Always doubled"

Always doubled

Knowing the periods of revolution of the planets and using his third law, Kepler was able to "Find the relative distances of the planets from the Sun." "Determine the circumference of the Earth." "Determine the distance between the Earth and the Sun." "Find the distance between Earth and the Moon." "Find the speed of the planets as they circled the Sun."

Find the relative distances of the planets from the Sun.

Your weight is a measure of Rotational equilibrium Gravitational attraction Energy Momentum All of the other answers are correct

Gravitational attraction

If a constant force is applied to an object of decreasing mass, the acceleration is Increased Decreased Constant

Increased

According to the law of equal areas developed by Kepler, the speed of a planet _______ . "Constantly increases with time" "Is constant in all parts of its elliptical orbit" "Is greatest when the planet is closest to the Sun" "Is greatest when the planet is farthest from the Sun" "Changes because the masses of the planets change"

Is greatest when the planet is closest to the Sun

An object is thrown vertically into the air in the presence of air resistance. The time for its descent will be Shorter than the time of its ascent Longer than the time of its ascent Equal to the time of its ascent

Longer than the time of its ascent

An astronaut on another planet drops a 1-kg rock from rest and finds that it falls a vertical distance of 4 meters in one second. On this planet the rock has a weight of "4 N" "5 N" "1 N" "4.9 N" "None of the other answers is correct"

None of the other answers is correct"

Kepler's second law states that the line joining the Sun to a planet "Moves fastest when the planet is farthest from the Sun." "None of the choices given here is correct." "Sweeps out equal areas in equal times." "Moves slowest when the planet is nearest the Sun." "Sweeps out an area equal to the cube of its length."

Sweeps out equal areas in equal times.

Copernicus was correct in saying that "The Earth is the center of the solar system." "The Earth revolves around the Sun." "The Sun is the center of the universe." "Planets revolve around the Sun in elliptical orbits." "The planets move along epicycles."

The Earth revolves around the Sun.

A push on a one kilogram brick accelerates the brick. To equally accelerate a 10 kilogram brick, one would have to push "With just as much force" "None of the other answers is correct" "With 10 times as much force" "With 100 times as much force"

With 10 times as much force

A bullet fired horizontally hits the ground in one-half second. If it had been fired with a high speed in the same direction, it would have hit the ground in (neglect the Earth's curvature) Less than one-half second one-half second More than one-half second

one-half second