Midterm Review

Question 1

As the distance between two bodies increases, the force of attraction between the bodies ________ .

Answer 1

A. decreases

Question 2

The slope of a position versus time graph gives _______________________________.

Answer 2

average velocity

Question 3

An accelerating object travels _________________

Answer 3

slower during each second that it moves AND farther during each second that it moves

Question 4

Which encounters a greater force of air resistance, a falling elephant or a falling feather?

Answer 4

the feather

Question 5

The best measure of an object’s inertia is its ____.

Answer 5

mass

Question 6

The unit for power in the SI system is ____.

Answer 6

watt

Question 7

An object with mass m is thrown straight up. At its highest point, the net force on it is

Answer 7

mg

Question 8

What would the rate of speed of a man running 60 ft in 10 sec be?

Answer 8

6 ft/sec

Question 9

A block with a mass of 10 kg is located 30 m above a road. If the block fell, what would be its kinetic energy at the moment it struck the road? (PE = KE) (PE=mass x accel. of gravity x height) (accel. of gravity = 9.8m/secSQUARED)

Answer 9

3000 joules

Question 10

Efficiency of work is the ratio of work output to

Answer 10

work input

Question 11

What is the force called with which the earth pulls on an object?

Answer 11

gravity

Question 12

The transfer of energy by mechanical means is

Answer 12

work

Question 13

A negative linear acceleration indicates that an eastward moving object is

Answer 13

slowing down

Question 14

The ___ component(s) of a projectile’s velocity will change while the projectile is in the air.

Answer 14

vertical (Vy)

Question 15

Which of the following is not a type of energy?

Potential Kinetic Heat Cold

Answer 15

Cold

Question 16

A pendulum at the bottom of its swing is an example of ___ energy.

Answer 16

kinetic

Question 17

A rock is thrown from a catapult at an angle of of 25 degrees above the horizontal with an initial velocity of 45 m/s. Find the horizontal and vertical components of the rock’s initial velocity

Answer 17

41m/s, 19 m/s

Question 18

When an object is in motion it is said to have

Answer 18

kinetic energy

Question 19

In what direction does friction act with respect to the motion of a sliding object?

Answer 19

in the opposite direction

Question 20

A quantity that has both magnitude and direction is referred to as

Answer 20

vector

Question 21

If you raised a physics book 5 m, it gains a certain amount of PE . However, if you raised another book (with the same mass) 10 m, its PE is

Answer 21

twice as much

Question 22

The equation to find the weight of an object is

Answer 22

weight = mass x g

Question 23

When a body is at rest, _____

Answer 23

all of the forces are in balance

Question 24

Newton’s second law of motion tells us that as the force on an object increases, the acceleration

Answer 24

increases

Question 25

A dog swims west across a river at 3.0 m/s relative to the river that flows north at 5.0 m/s. Find the magnitude and direction of the dog's resultant velocity.

Answer 25

5.8m/s, 31 degrees W of N

Question 26

You are standing n a moving bus, facing forward, and you suddenly fall backward. You can imply from this that the bus's

Answer 26

velocity increased

Question 27

An object weighing 40N on the earth's surface would weigh only 10 N when its distance from the center of the earth is

Answer 27

doubled

Question 28

Which best describes the maximum height a projectile reaches?

Answer 28

Dy

Question 29

Stored energy is ___ energy

Answer 29

potential

Question 30

An apple hanging in a tree has potential energy equal to its weight multiplied by its

Answer 30

height in the tree

Question 31

The tendency of an object to resist change in its motion is called

Answer 31

inertia

Question 32

Which of the following is the correct unit for kinetic energy in the SI system? Watt? Newton? Joule? Joule/sec

Answer 32

Joule

Question 33

If the mass of the earth were to double with no change in size, your weight would

Answer 33

increase

Question 34

"Energy can neither be created nor destroyed." This means that a system's total energy remains constant. This is the Law of Conservation of

Answer 34

energy

Question 35

When the same net force is applied to two blocks, the yellow one has a larger acceleration than the blue one. Which of the following is correct? The yellow block has a larger mass? They have the same mass? The blue block has a larger mass?

Answer 35

The blue block has a larger mass.

Question 36

A Newton is defined as

Answer 36

kg m/sSQUARED

Question 37

Power is defined as

Answer 37

the rate at which work is being done

Question 38

Your teacher has walked from the physics room around the entire school and back to the physics room. Your teacher's displacement is

Answer 38

Zero

Question 39

A box weighs 25 N on earth. A second box weighs 25 N on the moon. which as the greater mass?

Answer 39

The one on the moon.

Question 40

A ball falling from a great height will reach terminal velocity when _________________.

Answer 40

the force of air resistance equal its weight

Question 41

The slope of an distance vs. time graph will tell _____________ .

Answer 41

velocity

Question 42

Ignoring air resistance, the horizontal component of a projectile’s acceleration _______________.

Answer 42

is zero

Question 43

According to Newton's _____ Law, an object at rest stays at rest and an object in motion stays in motion when no net force acts on it.

Answer 43

1st

Question 44

For every action force, the reaction force is a(n) ___.

Answer 44

equal and opposite in direction

Question 45

What is the mass of an object that weighs 150N on earth?

Answer 45

15 kg

Question 46

The acceleration due to gravity here on earth is numerically equal to

Answer 46

9.8 m/secSQUARED

Question 47

190mm =

Answer 47

0.19

Question 48

48. An Atlanta Braves pitcher drops a baseball into the Chattahoochee River from a very high bridge while a pitcher from the Boston Red Sox throws one straight down from the same bridge. Ignoring air resistance, the vertical acceleration just before striking the water ___________ .

Answer 48

is the same for both baseballs

Question 49

According to Newton's ___Law of Motion, an object with no net force acting on it remains at rest or in motion with a constant velocity.

Answer 49

1st

Question 50

An object sits on a frictionless surface. A 16 N force is applied to the object, and it accelerates at 2 m/sSQUARED. The mass of the object is ______________ .

Answer 50

8 kg

Question 51

51. Two cantaloupes are dropped at the same time from the 7.5 m tall stadium bleachers. If the first cantaloupe weighs 1.5 N & the second cantaloupe weighs 5.0 N, then which cantaloupe hits first? Neglect air resistance.

Answer 51

both reach the ground at the same time

Question 52

According to Newton's Law of Universal Gravitation, the force of attraction between any two masses is related directly to ________

Answer 52

the product of the masses

Question 53

The physics teacher can go up a flight of stairs in 20 seconds. If the physics teacher weighs 600 N and the vertical height of the stairs is 10 m, the teacher’s power output is _____.

Answer 53

300 W

Question 54

While attempting to follow the directions on a map, a hiker walks 45.0 meters south, then turns to the west and walks 7.5 meters. What is the hiker’s displacement?

Answer 54

45.6 meters, 9.5 degrees west of south

Question 55

Mechanical work is done only when a force _______.

Answer 55

moves an object

Question 56

The rate at which velocity changes is _____.

Answer 56

acceleration

Question 57

Projectiles are objects that are given an initial velocity and then move only under the influence of ___.

Answer 57

gravity

Question 58

Work done by a machine is usually accomplished _____.

Answer 58

by converting energy from one form to another

Question 59

If the mass and weight of an astronaut are measured on the earth and on the moon, we will find that the masses are ___ and the weights are ___.

Answer 59

the same . . . different

Question 60

A 4 kg ball is thrown at 2 m/s. The ball's momentum is

Answer 60

8 kg m/s

Question 61

A student drops a rock from a bridge to the water 12.0 meters below. How long does it take the rock to hit the water?

Answer 61

1.2 s

Question 62

An airplane travels at 165 km/hr northwest. What is the plane's displacement if it travels for 3.5 hours?

Answer 62

577.75 km NW

Question 63

an object with a mass of 10-kg is moving at a speed of 2 meters per second. Calculate the kinetic energy in joules. [KE=1/2mvSQUARED]

Answer 63

20-J

Question 64

A brick is thrown downward form the top of a building with an initial speed of 25 m/s. It strikes the ground after 2 s. How high is the building?

Answer 64

70 m

Question 65

A rock is thrown from a catapult at an angle of 25 degrees above the horizontal with an initial velocity of 45 m/s. Find the vertical and horizontal components of the rocks initial velocity.

Answer 65

41 m/s, 16 m/s

Question 66

Centripetal forces always act in which direction?

Answer 66

toward the center

Question 67

A force is directly proportional to

Answer 67

mass, acceleration

Question 68

Which of the following has kinetic energy? A baseball in flight. A rock located 6 ft above the ground. An inflated balloon. . A bow string that is stretched just before release.

Answer 68

A baseball in flight.

Question 69

If we graph velocity vs. time for a moving object, what is the slope?

Answer 69

acceleration