Con-Physics Final Exam

(Chapter 5) You push with 30 N on a 3-kg block and there are no opposing forces. What is the block's acceleration?

10 m/s^2

(Chapter 5) A 50-kg block of cement is pulled upward (not sideways!) with a force of 600 N. What is its acceleration?

12 m/s ^2

(Chapter 8) How much work is done in lifting 30 kg of bricks to a height of 20 m?

6000 J

(Chapter 6) A 60-kg person on in-line skates pushes against a wall with a force of 30 N and recoils. what acceleration does that person experience?

A = .5 m/s^2

(Chapter 17) T or F: Matter is commonly found in three phases. These phases are solid, liquid, and gaseous.

True

(Chapter 17) T or F: Most of the mass an atom is in its nucleus

True

(Chapter 17) T or F: The number of protons an atom has in its nucleus is same as its atomic number

True

(Chapter 17) T or F: When the number of electrons does not equal the number of protons in an atom, the atom has a charge and is called an ion

True

(Chapter 5) T or F: Air resistance is cause by friction between the air and an object moving through air

True

(Chapter 6) T or F: A rocket ship is pushed forward by gases that are forced out the back of the ship.

True

(Chapter 6) T or F: Whenever one object exerts a force on a second object, the second object always exerts the same amount of force back on the first object.

True

(Chapter 6) The earth and moon pull on each other with equal amounts of force.

True

(Chapter 7) T or F: If a net force acts on a system, the system's momentum will change.

True

(Chapter 7) T or F: The padding on a car dashboards lengthens the time of a passenger's impact during a collision?

True

(Chapter 8) T or F: The energy an object has by virtue of its motion is called its kinetic energy

True

(Chapter 8) T or F: The engery an object has by virtue of its location is called its potential energy

True

(Chapter 8) T or F: The rate at which work is done is called power

True

(Chapter 9) T or F: Any force that causes an object to move in a circular path is called a centripetal force

True

(Chapter 9) T or F: It is possible to rotate a very large cylindrical space habitat around its central axis at just the right speed so people inside the cylinder will experience a force that feels like gravity

True

(Chapter 9) T or F: The outside from of a rotating turntable has a greater linear speed than parts closer to the axis.

True

(Chapter 7) A 30-kg girl and a 25-kg boy face each other on friction-free roller skates. The girl pushes the boy, who moves away at a speed of 1.0 m/s. What is the girl's speed?

V1 = .83 m/s

(Chapter 5) What is terminal speed? When a skydiver had reached terminal speed, what is he air resistance equal to? What is skydiver's acceleration?

When you've reached maximum speed. When air resistance and weight are equal and there is a net force of zero. The skydiver's air resistance is equal to his weight.

(Chapter 8) How much work is done on a 50N rock that you lift 10 m straight up? a. 500 J b. 50 J c. 10 J d. 1 J

a. 500 J

(Chapter 8) How much power is expended if you lift a 50-N rock 10 meter s in 1 second? a. 500 W b. 50 W c. 10 W d. 5 W

a. 500 W

(Chapter 6) Whenever an object exerts a force on another object, the second object exerts a force of the same magnitude, but in the opposite direction to that of the first object. a. always true b. sometimes true c. always false

a. Always true

(Chapter 5)As he falls from a high-flying stationary helicopter, Bronco's velocity increases and his acceleration... a. decreases b. remains the same c. increases

a. decreases

(Chapter 17) Which element comprises over 90 percent of the known atoms in the Universe? a. Hydrogen b. oxygen c. nitrogen d. carbon

a. hydrogen

(Chapter 6) An unfortunate bug splatters against the windshield of a moving car. Compared tot he deceleration of the car, the acceleration of the bug is a. larger b. smaller c. the same

a. larger

(Chapter 8) An object that has kinetic energy must be a. moving b. falling c. elevated d. at rest

a. moving

(Chapter 17) When a nucleon is electrically neutral, it is called a. a neutron b. a proton c. an electron d. an isotope

a. neutron

(Chapter 17) Elements that are side by side in the periodic table have one more or one less a. protons b. nucleon c. electron shell d. isotope

a. protons

(Chapter 17) Atoms are a. smaller than the wavelength of visible light b. small, but you can see them with a microscope c. seen only through a microscope looking through another microscope d. so small that we can never see them, with any kind of microscope

a. smaller than the wavelength of visible light

(Chapter 7) Which has more momentum, a large truck moving at 30 miles per hour r a small truck moving at 30 miles per hour? a. the large truck b. the small truck c. both have the same momentum

a. the large truck

(Chapter 9) Which has greater linear speed, a horse near the outside rail of a merry-go-round or a horse near the inside rail? a. the outside horse b. the inside horse c. neither - they both have the same linear speed

a. the outside horse

(Chapter 17) What are the differences among atoms, molecules and compounds?

an atom is the smallest part of an element that still has the characteristics of that element. a molecule are two or more atoms that combine to make a larger particle such as in nature you will never find naturally one atom a compound is two or more elements that come together chemically and form a substance that has different properties than the elements, comes together in fixed proportions

(Chapter 6) As a 500 N woman sits on the floor, the floor exerts a force on her of a. 1000 N b. 500 N c. 250 N d. 50 N

b. 500 N

(Chapter 6)A woman weighing 500 N sits on the floor. She exerts a force on the floor of a. 1000 N b. 500 N c. 250 N d. 50 N

b. 500 N

(Chapter 8) An arrow in an box has 70 J of potential energy. Assuming no energy loss, how much kinetic energy will it have after it has been shot? a. 140 J b. 70 J c. 50 J d. 35 J

b. 70 J

(Chapter 5) Which of the following would exert the most pressure on the ground? a. a woman standing in running shoes b. a woman standing in high heel shoes c. a woman standing on skis

b. a woman standing in high heel shoes

(Chapter 8) If Skelly the skater's speed is increased so he has twice the momentum, then his kinetic energy is increased by a. two b. four c. eight d. zero

b. four

(Chapter 8) A car that ravels twice as fast as another when braking to stop will skid a. twice as far b. four times as far c. depends on the mass of the cars

b. four times as far

(Chapter 7) The cannonball launched from a cannon with a long barrel will be faster because the cannonball receives a greater a. force b. impulse c. both of these d. neither of these

b. impulse

(Chapter 17) Nearly all the elements heavier than hydrogen that exist today were created a. at the same time the universe was created b. in the deep interior of the stars c. in the center of the earth d. by collisions in deep space

b. in the deep interior of the stars

(Chapter 9) What is the direction of the force that acts on clothes in the spin cycle of a washing machine? a. outward b. inward c. up d. down

b. inward

(Chapter 5) If the force acting on a cart doubles, what happens to the cart's acceleration? a. it quadruples b. it doubles c. it halves d. it quarters

b. it doubles

(Chapter 7) If superman at rest in free space throws an asteroid that has more mass than superman, then which moves faster? a. the asteroid b. superman c. they both move at the same speed

b. superman

(Chapter 5) A tennis ball and a solid steel ball the same size are dropped at the same time. Which ball has the greater force acting on it? a. the tennis ball b. the steel ball c. they both have the same force acting on them

b. the steel ball

(Chapter 8) If you lift one load up two stories, how much work do you do compared to lifting one load up only one story? a. four times as much b. twice as much c. the same amount d. one half as much

b. twice as much

(Chapter 7) Compared to a sports car moving at 30 miles per hour, the same sports car moving at 60 miles per hour has a. the same momentum b. twice as much momentum c. four times as much momentum

b. twice as much momentum

(Chapter 6) If a horse pulls on a wagon at rest, the wagon pulls back equally as much on the horse. Will the wagon be set into motion? a. No, because the forces cancel each other. b. yes, because there is a net force acting on the wagon c. yes, because there is a time delay between action and reaction d. yes, because the hire's pull on the wagon is larger than the wagon's pull on the horse

b. yes, because there is a net force acting on the wagon

(Chapter 9) People in the future may well live inside a rotating space structure that is more than 2 km in diameter. inside the structure, people on the inside of the outer edge will experience 1 g while people halfway to the axis will experience a. 2 g b. 1 g c. 1/2 g d. 1/4 g

c. 1/2 g

(Chapter 17) Sometimes an atom has more or fewer electrons than it does protons. Such an atom is called a. a molecule b. a compound c. an ion d. an isotope

c. an ion

(Chapter 9) If you whirl a tin can on the end of a string and the string suddenly breaks, the can will a. fly directly away from you b. fly directly toward you c. fly off, tangent to its circular path d. spiral away from your hand

c. fly off, tangent to its circular path

(Chapter 5) Pressure is defined as... a. distance per unit time b. force per unit time c. force per unit area d. velocity per unit time

c. force per unit area

(Chapter 8) If nellie Newton pushes an object with twice the force for twice the distance, she does a. the same work b. twice the work c. four times the work d. eight times the work

c. four times the work

(Chapter 7) The momentum change of an object is equal to the a. force acting o it b. velocity change of the object c. impulse acting on it d. object's mass times the force acting on it

c. impulse acting on it

(Chapter 6) Forces always occur a. when velocities are constant b. as single quantities c. in pairs d. in triplets

c. in paris

(Chapter 17) Atoms combine together to form a. nucleons b. elements c. molecules d. isotopes

c. molecules

(Chapter 9) Which has greater angular speed, a horse near the outside rail of a merry-go-round or a horse near the inside rail? a. the outside hors b. the inside horse c. neither - they both have the same angular speed

c. neither. they both have the same angular speed

(Chapter 5) A tennis ball and a solid steel ball the same size are dropped at the same time. In the absence of air resistance, which ball has the greater acceleration? a. the tennis ball b. the steel ball c. nonsense! they both have the same acceleration

c. nonsense! they both have the same acceleration

(Chapter 17) At the center of every atom is a mass-filled region called the a. nucleon b. neutron c. nucleus d. ion

c. nucleus

(Chapter 6) A high school student hits a nail with a hammer. During the collision, there is a force a. on the hammer but not the nail b. on the nail but not on the hammer c. on the nail and also on the hammer

c. on the nail and also on the hammer

(Chapter 9) A ladybug rests on the bottom of a tin can that is being whirled in a horizontal circle at the end of a string. What exerts the force that holds this ladybug in a circle? a. your hand b. the string c. the can d. gravity

c. the can

(Chapter 6) An unfortunate bug splatters against the windshield of a moving car. Compared to the force of the car on the bug, the amount of force of the bug on the car is a. larger b. smaller c. the same

c. the same

(Chapter 7) A ping-pong ball launcher is fired. Compared too the impulse on the ball, the amount of impulse on the launcher is a. larger b. smaller c. the same

c. the same

(Chapter 5) A girl whose weight is 200 N hangs from a bar supported by two strands of rope. What is the tension in each strand? a. 400 N b. 300 N c. 200 N d. 100 N

d. 100 N

(Chapter 5) The acceleration produced by a net force on an object is... a. directly proportional to the magnitude of the net force b. in the same direction as the net force c. inversely proportional to the mass of the object d. all of the above

d. all of the above

(Chapter 7) If the momentum of an object changes and its mass remains constant a. its velocity is chaining b. it is accelerating (or decelerating c. there is a force acting on it d. all of the above

d. all of the above

(Chapter 7) Skelly the skater traveling at high speed needs a certain amount of force to stop him. More stopping force will be needed if he has a. more mass b. more momentum c. less stopping distance d. all of these

d. all of these

(Chapter 17) There are slightly more than 100 known atoms that combine to form all living and nonliving matter that we know about. These atoms are called a. isotopes b. nucleons c. molecules d. elements

d. elements

(Chapter 9) Which of the following is NOT a unit of rotational speed? a. revolutions per second b. rotations per second c. revolutions per minute d. meters per second

d. meters per second

(Chapter 17) Most of the matter of the universe is in which phase? a. liquid b. solid c. gas d. plasma

d. plasma

(Chapter 9) A tin can whirled on the end of a sting moves in a circle because a. once the can starts moving, that is its natural tendency b. the can continually pulls on the string c. there is a force on the can pulling it outward d. the string continually pulls inward on the can

d. the string continually pulls inward on the can

(Chapter 7) A railroad diesel engine coasting at 10 km/h runs into a stationary flatcar. The diesel weighs 4 times as much as the flatcar. Assuming the cars couple together, how fast are they moving after the collision?

m1v1 +m2v2 = mv v = 8 km/hr

(Chapter 6) Apply Newton's third law to a falling boulder, identifying the action and reaction forces. If a force is exerted on the earth, why doesn't it move?

If the boulder is running into air molecules, the molecules are running into it. The earth is so large that the impact is so small.

(Chapter 9) Discuss the difference between linear speed and rotational speed. Where does a ladybug sitting on a rotating record have the greatest linear speed? The greatest rotational speed? What kind of speed would she have at the center?

On the outside edge. It doesn't matter, it's all the same, all of the points are connected. 0 speed in the center

(Chapter 7) What is the average momentum of a 70-kg runner who covers 400 m in 50 s

P = 560 kg x m/s

(Chapter 8) Discuss who energy conservation applies to a pendulum. Where is potential energy the most? The least? Where is kinetic energy the most? The least? Where is the pendulum accelerating the most? The least? Where is it moving the fastest? Stopped?

Potential energy is at its max at the peak and the least at the bottom. Vice versa for kinetic. Accelerations is its greatest when it goes from zero. Lowest point is where velocity is the greatest. Least at the bottom

(Chapter 6) A boxer punches a sheet pf paper in midair, and brings it from rest up to a speed of 40 m/s in 0.05 s. If the mass of the paper is 0.01 kg, what is the force of impact on the paper?

F = 8 N

(Chapter 17) T or F: Atoms are the smallest particles that exist

False

(Chapter 5) T or F: Objects move only when a force is exerted

False

(Chapter 6) T or F: If a bicycle and a parked car have a head-on-collision, the force of impact is greater on the bicycle.

False

(Chapter 6) T or F: In order to make a cart move forward, a horse must pull harder on the cart than the cart pulls on the horse.

False

(Chapter 7) T or F: After a firecracker falling through the air explodes, the net momentum of its fragments decreases.

False

(Chapter 7) T or F: If the net external force acting on a system is zero, then the oral momentum of the system is zero.

False

(Chapter 7) T or F: Impulses are smaller when bouncing takes place.

False

(Chapter 9) T or F: A bug on a turntable will make more turns per minute if it is located nearer to the center of the record

False

(Chapter 9) T or F: When you whirl a can on the end of a string, the centripetal force on the car is actually the pull of the string on the can

False

(Chapter 8) T or F: More power is need to carry a heavy suitcase slowly up a flight of stairs than to cary the suitcase quickly up the same flight of stairs

False, More power is need to carry a heavy suitcase quickly up a flight of stairs than to cary the suitcase slowly up the same flight of stairs

(Chapter 8) T or F: The ration of output force to input force for a simple machine is called its efficiency

False, called its mechanical advantage

(Chapter 5) T or F: The speed of an object dropped in air will continue to increase without limit

False, increase with a limit and the limit is called terminal velocity

(Chapter 5) T or F: The acceleration of an object is inversely proportional to the net force acting on it

False, it is directly proportional to the net force acting on it

(Chapter 5) T or F: Pressure is defined as the force on object exerts o another object.

False, pressure is the amount of force over a given area