Conceptual Physics

Midterm Exam Review

January 2009

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Date: ______

Period: ______

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Park View High School

Sterling, Virginia

PART I MULTIPLECHOICE

Use the Following graphs to answer Questions 1-3

time (s)time (s)

  1. Determining the slope of the position time curve will give you what quantity?
  1. Determining the slope of the velocity time curve will give you what quantity?
  1. If you take the area under a velocity time curve you would of calculated what quantity?
  1. Suppose you drive to Leesburg, which is 40 km away. What is your average velocity if it takes 0.75 hours to drive to Leesburg?
  1. Along the way to Leesburg you stop at a red light. When the light turns green you go from rest (0 m/s) to 20 m/s in 5 seconds. What is your average acceleration?

Use the following Graph to answer Questions 6 - 8

A B C D

100

90

80

70

60

50

40

30

20

10

0

0 2 4 6 8 10 12 14 16 18 20 22 24 26

  1. What is the acceleration of the particle during the A – B interval?
  1. What is the acceleration of the particle during the B – C interval?
  1. What is the acceleration of the particle during the C – D interval?

Use the sketch below of a ball rolling at constant velocity (5 m/s) on a floor into a wall to answer questions 9 - 11

5 m/s

25.0 m

  1. How long will it take the ball to roll the length of the floor (25m)?
  1. When the ball has rolled 15 m what is it velocity?
  1. What is the ball’s velocity when it strikes the wall?
  1. A man walks 100 m east and turns around and walks 5 meters west as shown below.

10 m east

50 m west

What is his displacement?

Suppose you drop a penny of the Empire state building in New York City as shown in the diagram below. Ignoring air resistance answer questions 13 - 16

  1. What is the velocity of the penny after 1 second?
  1. What is the velocity of the penny after 5 seconds?
  1. How far did the penny fall in 1 second?
  1. How far did the penny fall in 5 seconds?

  1. A ball rolls down a curved ramp as shown in the diagram below. Draw a dotted line that best represents the path of the ball after leaving the ramp?

floor

  1. Above the ground, an arrow A, is shot horizontally from a bow at a speed of 20 m/s, as shown in the diagram below. The second arrow, B, is dropped from the same height and at the same instant as A is shot.

B A

Ground

Neglecting air friction, compare the amount of time A takes to strike the ground to the amount of time B takes to strike the ground.

  1. The diagram below shows a projectile moving with speed v at the top of its trajectory.

V

Ground

Draw a vector which best represents the acceleration of the projectile in the position shown?

  1. The diagram below shows a baseball being hit with a bat. Angle represents the angle between the horizontal and the ball’s ignition direction of motion

Baseball

Horizontal Line

A what angle should the baseball be thrown at that would result in the ball traveling the longest horizontal distance?

  1. A ball is projected horizontally to the right from a height of 50 meters as shown in the diagram below.

Draw a diagram which would best represent the path of the ball at 1.0 second intervals?

  1. The diagram below shows the muzzle of a cannon located 50 meters above the ground. When the cannon is fired, a cannonball leaves the muzzle of the cannon with an initial velocity of 250 m/s.

50 m

What could you do to increase the time of flight of the ball fired by the cannon?

  1. A boy stands on a cliff and throws a ball at a velocity of 50 m/s horizontally off the cliff. Would you choose a tall or short cliff if the boy wanted to give a ball the longest range?
  1. In the diagram below a stationary observer on a life raft watches a coastguard plane flying horizontally with velocity “V” to the right drop, a care package

V

Draw a diagram which would represent the path of the path the care package will take as seen by the man in the life raft?

  1. Park View softball player hits a homerun while playing Stone Bridge. After the game she describes the homerun to her parents. What word would best describe the trajectory of the ball?

Ground

  1. A cannon is set on a hill that is 75 meters high. What could you do to the speed of the cannon to give it the longest range?
  1. An astronaut is in outer space, he is far away from gravitational or frictional forces. He throws a rock. Describe what will happen to the speed of the rock.
  1. An astronaut is in outer space, he is far away from gravitational or frictional forces. He throws a rock. The best way to describe path of the rock would how.
  1. The sketch below shows a top view of a rock being whirled at the end of a string (clockwise). The string Breaks. Draw a like which represents the path the rock would take.
  1. Write the formula for calculating a net Force.

Suppose you are standing in the isle of a bus that travels along a straight road at 75 km/hr, and you hold a pencil still above your head.

  1. Then relative to the bus, what would be the velocity of the pencil.
  1. Relative to the road, what would be the velocity of the pencil.
  1. Suppose you release the pencil, while it is dropping, and relative to the road, the pencil has a horizontal velocity equal to ______km/hr.
  1. This means that the pencil will strike the floor where?
  1. Describe relative to you, how the pencil will fall.
  1. If 40 Newton’s of Force is applied to the box at constant velocity.

What is the frictional force acting on the box.

  1. A block sits motionless on a table as shown

What is the net force acting on the block?

  1. A box is falling at terminal velocity as shown. If the weight of the box is 65 Newtons

Air Resistance

Weight

What is the force of air resistance acting on the block?

Use the following diagrams to answer questions 39 - 41.

A

B

C

  1. Which ball will accelerate?
  1. Which ball will decelerate?
  1. Which ball will travel at a constant speed.

A crate filled with bananas rest on a warehouse floor. Use the diagram below to answer questions 42 – 45

P

W

  1. When only gravity and the support force of the floor act on the crate the net force acting on the crate will equal ______.

  1. A warehouse worker exerts a slight pull (P) on the crate, not enough to move it however, a force of friction F now acts on the crate compared the friction (F) force to the pulling (P) force.
  1. The warehouse worker increases his force P and the crate begins to move with constant velocity across the warehouse floor. Compare the force of friction F with the pulling (P) force.
  1. The warehouse worker pulls harder and P is further increased and is now greater than friction force F, will there be a net force acting on the crate?

Using the diagram below of a 5 N book resting on a bookshelf answer questions 46 – 50

W

  1. To say that the weight of the book is 5 N is to say that the downward gravitational force of 5 N is exerted on the book, caused by what?
  1. The bookshelf supports the book with normal force , which acts in a direction opposite. How does the compare to the weight.
  1. Since the book is at rest, what is the net force on the book?
  1. To assume = W, is an application of which one of Newton’s three laws?
  1. Suppose the bookshelf suddenly breaks. Why does the book falls straight down?
  1. What is the momentum of a 30-kilogram cart moving with a speed of 10 meters per second?
  1. An object traveling at 4.0 meters per second has a momentum of 16 kg-m/sec. What is the mass of the object?
  1. The product of an object’s mass and velocity is equal to
  1. If the speed of a moving object is doubled, which quantity associated with the object must also double?
  1. When mass is ______and velocity is ______an object has the greatest momentum.
  1. A man jumps into a fireman’s net to save him from a burning building. He survives without a scratch mainly because

(a.) he had a smaller change in velocity than if he had jumped onto the pavement

  1. A moving car has momentum. If it moves three times as fast, its momentum increases by how much?
  1. Compare the momentum of a gun that kicks back with the momentum of the bullet it fires.
  1. What is the impulse applied to a 750 kg car when it goes from 10 m/s to 25 m/s?
  1. A 2 kg cart and a 1 kg cart sit at rest on a Pasco track. Immediately after the plunger is pressed the cars move off in opposite directions. The 2 kg cart has a velocity of 5 m/s. What is the velocity of the 1 kg cart?

Velocity –

Acceleration –

Average Speed –

Vector Quantity-

Components-

Conservation of Momentum -

Projectiles-

Friction-

Force-

Impulse-

Inertia-

Newton’s First Law-

Newton’s Second Law-

Newton’s Third Law-

Air Resistance-

Pascal-

Terminal Velocity-

Action Force-

Reaction Force-

Mass-

Momentum -

Weight-

Net Force-

Support Force-

Normal Force-

Newton-

PART III CALCULATIONS

1. Determine the magnitude and direction of the net force on the box. Determine the resultant acceleration of the 5 kg box.

Applied Force

/ Net Force / Acceleration

20 N

30 N /


20 N 30 N /

20 N 20 N
/

2. Determine the reading on the scale Example

(1) (2)

(3)

4. The following 40 kg box is being pulled with a net force of 400 N

400 N

What is the acceleration of the box?

5. Use the following diagram to help answer the following questions.

(a)Suppose you pull on the box with 50 N of force. The box moves at constant velocity. What is the friction force?

(b)Suppose you pull on the box with 90 N of force. If the friction force remains constant what is the net force on the box?

(c) If the box has a mass of 10 kg what is the acceleration on the box?

6. Use the following diagram to help answer the following questions.

Air Resistance

Weight

(a)What is the weight of the 60 kg box?

(b)Suppose while falling the 60 kg package reaches terminal velocity. What is the force of air resistance?

7. While standing on a 80 m tall building in New York City you want to toss a baseball to a friend located on the top of a 40 m tall building next door as shown below.

40 m

50 m

  1. If the difference between the heights of the two buildings is 40 m how much time does it take for the baseball to reach your friend?
  1. If you are 50 m away from each other how fast must you throw the baseball to make sure your friend catches it?

8. You stand on the top of a hill 75 m high and shoot an arrow at 25 m/s as shown.

75 m

? m

  1. How long does it take the arrow to reach the ground?
  1. How far away from the base of the cliff will the arrow land?

#9.a.) Before the collision: 6 kg Ball A is moving at 4 m/s into stationary 2 kg Ball B. After the collision: Ball A is moving at 2 m/s, what is the resultant velocity of Ball B?

b.) Before the collision: 2 kg Ball A is moving at 4 m/s into stationary ball 6 kg Ball B. After the collision: Ball A is moving at - 1.0 m/s, what is the resultant velocity of Ball B?