midterm review

Question 1

which of the following is true for an ob ject traveling in a circular path at a constant speed

Answer 1

its speed is constant but its velocity is changing

Question 2

astronauts float in space because

Answer 2

the astronauts are falling with an acceleration so the normal force is zero

Question 3

Which of the following would make you weigh half as much as you do right now

Answer 3

take away half of the earth’s mass

Question 4

a car travels in a circle with constant speed. the net force on the car

Answer 4

is directed towards the center of the curve

Question 5

suppose the gravitational force between two massive spheres is 100n. if the distance between the spheres is doubled, what is the force between the masses?

Answer 5

25n

Question 6

if a car had more mass, its turning radius would be

Answer 6

the same as before

Question 7

if the coefficient of friction were greater, the radius would be

Answer 7

smaller

Question 8

if the car were going faster, the radius would be

Answer 8

larger

Question 9

if the mass of the satellite were less, the speed must be

Answer 9

the same

Question 10

if the mass of the earth were less, the speed of the satellite must be

Answer 10

less

Question 11

if the radius of the orbit was increased, the speed must be

Answer 11

increased

Question 12

if two identical boats race around a semi circular turn and both are traveling at the same speed, which has the higher acceleration?

Answer 12

the boat on the inside

Question 13

if two identical boats race around a semi circular turn and both are traveling at the same speed, which has the higher net force on it?

Answer 13

the boat on the inside

Question 14

if two identical boats race around a semi circular turn and both are traveling at the same speed, which takes longer to complete the turn?

Answer 14

the boat on the outside

Question 15

as a ball falls, consider one force to be the pull of the earth’s mass on the ball. what is the pair to this force?

Answer 15

the pull of the ball’s mass on the earth

Question 16

a horse exerts 500N of force on a heavy wagon, causing it to accelerate. what force does the wagon exert on the horse?

Answer 16

500 N

Question 17

when a block reaches the bottom of the hill it then travels on a level, horizontal, frictionless surface. which describes the motion of the block

Answer 17

constant speed

Question 18

a bowling ball resting on the floor is given a brief push. a moment later, after the push, which os the following forces acts on the ball?

Answer 18

a normal force, gravity

Question 19

newtons first law

Answer 19

An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

Question 20

newtons second law

Answer 20

The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.

Question 21

newtons third law

Answer 21

for every force there is a reaction force that is equal in size, but opposite in direction.

Question 22

an airplane flies at a constant speed in a straight line. a bale of hay is dropped from the bottom of the plane. when the bale hits the ground, where is the plane?

Answer 22

the plane is directly over the bale

Question 23

two spheres of equal mass are projected horizontally off the edge of a 2.0m table. sphere A has a horizontal velocity of 5.0 m/s and sphere B has a horizontal velocity of 2.5 m/s. which ball will be in the air for a greater amount of time?

Answer 23

the same amount of time

Question 24

two spheres of equal mass are projected horizontally off the edge of a 2.0m table. sphere A has a horizontal velocity of 5.0 m/s and sphere B has a horizontal velocity of 2.5 m/s. where will they hit the flooor?

Answer 24

B will land half as far as x

Question 25

two tennis ball launchers are placed on the second and third floor of an apartment building. they launch balls A and B with the same velocity and at the same angle. which ball has the greater maximum height?

Answer 25

the Ball launched from the higher launcher

Question 26

two tennis ball launchers are placed on the second and third floor of an apartment building. they launch balls A and B with the same velocity and at the same angle. which ball has the greater time in the air?

Answer 26

the ball launched from the higher launcher

Question 27

two tennis ball launchers are placed on the second and third floor of an apartment building. they launch balls A and B with the same velocity and at the same angle. which ball has the greater acceleration during flight?

Answer 27

the same acceleration

Question 28

two tennis ball launchers are placed on the second and third floor of an apartment building. they launch balls A and B with the same velocity and at the same angle. which ball will land further from the base of the building?

Answer 28

the ball launched from the higher launcher

Question 29

with the modified atwoods, what is the net force?

Answer 29

the hanging mass

Question 30

with the modified atwoods, what is the system mass?

Answer 30

the mass of the cart

Question 31

what is the relationship between net force and acceleration

Answer 31

proportional

Question 32

what is the relationship between system mass and acceleration

Answer 32

inversely proportional

Question 33

if the hanging mass increases,

Answer 33

acceleration increases

Question 34

if the mass of the cart increases,

Answer 34

acceleration decreases