SIMPLE & COMPLEX MACHINES
Physical Science Chapter 3: Moving Objects
Lesson 1: What Causes Objects to Move or Stop Moving?
Forces: Pushes & Pulls
1. How can you know that a force exists if you cannot see the force?
2. What causes an object to move toward a magnet?
Gravity:
1. What is gravity?
2. What are the two factors that affect the force of gravity between two objects?
3. What evidence can we see on the earth of the pull of gravity between the moon
and the earth?
4. A force of attraction exists between the earth and a stone dropped from a bridge.
Which is greater, the pull the stone exerts on the earth or the pull the earth exerts
on the stone?
5. What happens to the force of gravity on a rocket as the rocket leaves Earth and
moves into space?
Mass and Weight:
1. What is mass?
2. What is the difference between mass and weight?
Balanced and Unbalanced Forces:
1. What do the arrows represent in the picture on page B84?
2. What is the term for the combination of all the forces acting on an object?
3. How do balanced and unbalanced force affect motion?
Lesson 2: How Is Motion Described?
Types of Motion: pg. B86-88
1. List and describe the three types of motion.
2. To see how fast a stream is flowing, you toss a piece of wood into the stream and
watch as the piece of wood floats past a large stone on the far bank. In this
example of relative motion, what term would be used to describe the stone?
3. A ferris wheel is an example of what type of motion?
4. A woman sits on a bench by the street as a bus goes by traveling west. Behind
her, a boy walks past going west, and a girl rides by on a bicycle going east.
Apply your understanding of relative motion to describe how the motion of the
bus appears different depending on which person you use as a frame of reference.
Distance and Displacement: pg. B88-89
1. What is distance & displacement?
2. A friend says that when he rides his bicycle from his home to the park, his
displacement is 200 m. What is wrong with this statement?
3. A teacher says that when she walks to the public library, she travels a distance of
80 m, and her displacement is 70 m west. What does this tell you about the path
she takes when walking to the library?
4. If you walk 110 m west, then 80 m north, then 110 m east, then 140 m south, what
is your total distance traveled? What is you displacement?
5. Cause & Effect: Your family is driving to a national park, and during the trip you
have to make a long detour around a bridge that is closed for repairs. What effect
does this detour have on your distance traveled and your displacement for the
trip?
6. Cause & Effect: Suppose the path of the racers on page B92 goes uphill at some
point. What effect will that most likely have on their velocity?
Speed and Velocity: pg. B90-91
1. What is the difference between speed and velocity?
2. You travel a distance of 150 km by car, and the trip takes 2 hours. What is your
average speed?
3. What is the name of a device that shows instantaneous speed?
4. What is the difference between instantaneous speed and average speed?
Acceleration: pg. B92-93
1. What are three ways an object can accelerate?
2. A car travels with zero acceleration along a road. What does this tell you about
the car’s motion?
3. Describe the acceleration of a runner during a 100 m race.
Lesson 3: What is Newton’s First Law of Motion?
Inertia and Motion: pg. B94-96
1. What does Newton’s first law say about the motion of all objects?
2. The inertia of an object is directly related to what other property of the object?
3. Have you ever had a drink spill while riding in a car? What usually causes this to
happen?
4. What happens to a moving object if no unbalanced for acts on it?
5. What is inertia? Does it affect moving objects or objects at rest?
6. A passenger in a car is not wearing a seat belt. Predict what happens to the
passenger when the car makes a sharp left turn.
7. How does inertia affect motion?
Friction: pg. B97-98
1. Explain why track-and-field athletes wear shoes with spikes on the bottom?
2. If you start a ball rolling across the floor, and it doesn’t hit any obstructions will it
keep rolling forever? Why or why not?
3. Friction converts energy of motion into what form of energy?
4. How does friction affect moving objects?
5. Cause & Effect: You can hold a pencil because of friction. Use cause & effect to
explain how this happens.
Circular Motion: pg. B99
1. How does Newton’s first law explain circular motion?
Lesson 4: What is Newton’s Second Law of Motion?
Mass, Force, Acceleration:
1. In what direction do objects accelerate?
Falling Objects:
1. According to Aristotle, the rate at which an object falls depends on what property
of the object? Was Aristotle correct?
2. How can a skydiver slow his fall toward the earth without using his parachute?
3. Why do objects fall at different rates?
Lesson 5: What is Newton’s Third Law of Motion?
Action & Reaction:
1. What are actions and reactions?
2. While you are at the park, you lean against a tree, pushing you on it with a force
of 90 N toward the east. What are the magnitude and direction of the force that
the tree exerts on you?
3. What would happen if the tree did not push back with equal force?
Newton’s Laws at the Amusement Park:
1. If you are on the ride on the bottom of page B108 and you are moving at a
constant speed, are you accelerating? Explain.
2. You are driving straight ahead in a bumper car, and your car bumps another car.
Apply your knowledge of Newton’s laws to describe what happens to you and
why.
3. Apply each of Newton’s laws to a ride in an amusement park.