PHYSICS FINAL REVIEW

a ball with a weight of 20 n is thrown vertically upward. what is the acceleration of the ball just as it reaches the top of its path?

10 m/s^2 downward

a football quarterback throws a long pass toward the end zone. assume that you can neglect the effects of air resistance. at the instant the ball reaches its hights point, what is the acceleration of the ball?

10 m/s^2 downward

what net force is needed to accelerate a 60 kg ice skater at 2 m/s^2?

120N

you are analyzing a problem in which two net forces act on an object. a 200 N force pulls to the right and a 40 N force pulls to the left. the net force acting on the object is....

160 N to the right

what is the acceleration due to earth's gravity ad a distance of one Earth radius above earth's surface?

2.5 m/s^2

after being hit, a baseball has a horizontal speed of 20 m/s and a vertical speed of 25 m/s upward. ignoring air resistance what are these speeds 1 s later?

20 m/s horizontal and 15 m/s vertical

suppose that you look out a 10h floor window and see a ball falling at 5 m/s. how fast will this ball be falling 2s later?

25m/s

which of the following forces does the most work? a force of ____acting through a distance of _____

3 N....3m

a 60 kg person on a merry-go-round is traveling in a circle with a radius of 3 m at a speed of 3 m/s. what is the magnitude of the acceleration experienced by this person?

3 m/s^2

what acceleration is produced by a force of 30 N acting on a mass of 10 kg?

3 m/s^2

Greg runs across the front of the classroom with a momentum of 300 kg*m/s and jumps onto a giant skateboard. the skateboard is initially at rest and has a mass equal to Greg's. if we ignore friction with the floor, what is the total momentum of Greg and the skateboard?

300 kg*m/s

a golf ball is thrown vertically upward with a speed of 30 m/s. how long does it take to get to the top of its path?

3s

if you double the radius of a sphere, its surface area increases by what factor?

4

what is the magnitude of the net force acting on an object which is under the influence of a 3 N force acting south and a 4 N force acting east?

5 N

which of the following objects has the largest kinetic energy? a mass of _____ with a speed of ___.

6 kg.... 3 m/s

a tennis ball is hit with a vertical speed of 10 m/s and a horizontal speed of 30 m/s. how far will the ball travel horizontally before landing?

60 m

two spacecraft in outer space attract each other with a force of 20 N. what would the attractive force be if they were one-half as far apart?

80 N

which of the following statements about projectile motion is true?

all of the above 1. the horizontal and vertical motions are independent 2. the acceleration of the projectile is constant throughout the flight 3. the force n the projectile is constant throughout the flight

which has the larger density, a gold brick or a gold coin?

both have the same density

two objects have different masses but the same kinetic energies. if you stop them with the same ???? force, which one will stop in the shorter distance?

both stop in the same distance

Newton's second law can be arranged to show that the _________ is equal to the ________.

change in momentum....... impulse

the kinetic energy of an object moving in a circle at a constant speed is

constant

you are riding an elevator from the parking garage in the basement to the 10th floor of an apartment. as you approach your floor, the elevator begins to slow. the net force acting on you is....

directed upward

if you hold the temperature of an ideal gas constant, what happens to its volume if you double its pressure? the volume....

is cut in half

a gun is held and fired. at the same time the bullet leaves, an identical bullet is dropped from the same height. which bullet will hit the ground first?

it will be a tie

if the bullets were not identical, but rather the dropped bullet has twice the mass of the other, which bullet would hit the ground first?

it will be a tie

which would hit the ground first if this experiment were conducted on the surface of the moon?

it will be a tie

if a sports car with a mass of 100 kg travels down the road with a speed of 20 m/s its kinetic energy is 200,000

kg*m^2/ s^2

which of the following is an energy unit?

kilowatt-hour

a ball is thrown straight up into the air. if we do not ignore air resistance, the acceleration for the ball as it is traveling downward is...

less than 9.8 m/s^2

which of the following is not a vector quantity?

mass

kinetic energy is defined to be 1/2 the.....

mass times the speed squared

which of the following properties of a ball is conserved as it falls freely in a vacuum?

mechanical energy

which of the following celestial bodies has the greatest influence on earth's tides?

moon

in physics, work is defined as the product of the....

net force parallel to the motion and the distance traveled

assuming that a planet is in a circular orbit about the sun, what is the force that drives the planet along its orbit; that is, tangent to the circle?

no force is needed to drive it along its orbit

which of the following is NOT a unit used for atmospheric pressure?

pounds per square inch

if the mass of an object in free fall is doubled, its acceleration....

stays the same

which of the following statements about Venus is not correct?

the Sun's gravitational pull on Venus equals Venus' gravitational pull on the Sun

in the strobe diagram below the ball is moving from left to right. which statement best describes the motion?

the ball is slowing down

A gun is held horizontally and fired. at the same time the bullet leaves the gun's barrel an identical bullet is dropped from the same height. neglect air resistance. Which bullet will hit the ground with the greatest velocity?

the bullet that was fired

which of the following statements about the Moon is correct?

the moon experiences a centripetal acceleration towards earth

which has the greater momentum, a heavy truck at rest or a moving roller skate?

the roller skate

If the mass and weight of an astronaut are measured on Earth and on the Moon, we will find that the masses are ____ and the weights are ____.

the same....different

the law of universal gravitation is written F=GMm/r^2. why did we use the form F=mg when we studied projectile motion?

the second form is a good approximation to the first and much simpler to use

how much work is performed by the gravitational force F on a synchronous satellite during one day?

zero, bc the force is perpendicular to the velocity

in a projectile motion the....

acceleration is vertical, while the velocity can be in any direction

over which of the following locations is it possible to have a synchronous satellite?

equator

which of the following is not a potential energy?

friction

a child stands on a bathroom scale while riding in an elevator. the child's weight when the elevator is not moving is 500 N. what does the scale read when the elevator accelerates upward while traveling downward?

greater than 500 N

a baseball player throws a ball from left field toward base plate. assume that you can neglect the effects of air resistance. at the instant, the ball reaches its highest point, what is the direction of the ball's velocity?

horizontal

the stunt person who is shot by a bandit and falls backwards from the balcony into an air bag rather than onto the ground will not be hurt because the....

increased stopping time means smaller stopping force

the 12-ounce boxing gloves used in amateur fights hurt less than the 6-ounce gloves used in professional fights because the ______ stopping times mean ____ forces

increased...smaller

in the law of universal gravitation the force____as the mass increases and _____as the distance increases.

increases......decreases