Force and Motion Study Guide
This study guide is meant to be a tool to help you prepare for your test. You should know all of the terms, equations and concepts that are on this study guide. However, I also suggest that you study your homework, labs, and quizzes because they are just as useful. While this study guide does cover some test material it might not cover all of the test material
A. Vocabulary:
1. force- the push, pull, or lift of an object
2. work- when you move or use force on something
3. machine- something that makes work easier
4. friction- the rubbing of one surface against another
5. weight- the measure of the pull of gravity on an object
B. Students should be able to list the five forces:
1. push
2. pull
3. friction
4. magnetism
5. gravity
C. Students should be able to describe the forces acting upon the ball in the picture below.
1. A push started the ball rolling.
2. At first, the force made the ball speed up.
3. The ball then rolled off the table and the force of gravity pulled it to the floor where it bounced.
4. Then the ball rolled on the floor and began to slow down due to the force of friction.
5. The ball rolled a short distance and then stopped.
D. Students should be able to answer questions about the following information:
q The three forces that act upon a paper airplane are push (from your hand), friction (from the air), and gravity.
q Friction can be harmful: pushing a big box across the floor, riding your bike through sand, scraping your knee
q Friction can be helpful: brakes on a bike, sand on an icy sidewalk, striking a match, using sandpaper to make a piece of wood smooth
The Driving Questions from this unit
How can motion be described?
How many different kinds of motions are there and what distinguishes them from one another?
If we roll a car down a hill, will it move at constant velocity or will it accelerate? Why do you think so?
Does the steepness of the hill make a difference in how the car will move? Why do you think so?
How could we find out if your ideas are correct?
What is force?
What is the nature of force (i.e. where do forces come from)?
What is the natural state of objects in regard to their motion?
Under what conditions will an object move with constant velocity?
Under what conditions will an object accelerate?
How do the forces that objects exert on one another compare?
How is acceleration related to force and mass?
What determines the rate at which objects fall?
What kind of motion do falling objects exhibit?
What determines the strength of the gravitational forces on objects?
What is air resistance and what factors influence it?
What effect does air resistance have on falling objects?
Define/explain the following terms:
Motion
Reference Point
Position
Distance
Displacement
Speed
Velocity
Acceleration
Force
Unbalanced Force
Inertia
Mass
Be able to
Explain what is described by each of Newton’s 3 Laws of Motion
Take a set of position and time data and determine the
Dt
Dx
average velocity of an interval
average velocity for the entire trip
acceleration of an interval
determine the kind of motion it represents
Analyze the motion represented on position vs. time graphs
Analyze the forces acting on an object and predict the kind of motion that will result.
Here are some common misconceptions related to force, do you still hold any of them?
· The only "natural" motion is for an object to be at rest.
· If an object is at rest, no forces are acting on the object.
· Only animate objects can exert a force. Thus, if an object is at rest on a table, no forces are acting upon it.
· Force is a property of an object. An object has force and when it runs out of force it stops moving.
· The motion of an object is always in the direction of the net force applied to the object.
· Large objects exert a greater force than small objects.
· A force is needed to keep an object moving with a constant speed.
· Friction always hinders motion. Thus, you always want to eliminate friction.
· Frictional forces are due to irregularities in surfaces moving past each other.
· Rocket propulsion is due to exhaust gases pushing on something behind the rocket.
· Acceleration always means that an object is speeding up.
· Acceleration is always in a straight line.
· Acceleration always occurs in the same direction as an object is moving.
· If an object has a speed of zero (even instantaneously), it has no acceleration.
.
1. Complete the following conversions, remember to show all of your work.
200m = mm
3000kg = cg
24 hours = seconds
100cL = kL
2. What are the steps of the Scientific Method?
3. List all three of Newton’s Laws and explain what they mean.
4. What is the difference between speed and velocity?
5. Name and define the two different types of variables.
Be able to use the following equations:
Speed Work N= kg m/s2
s = d W=Fd
t
Force Acceleration
F = ma a = vf - vi
t
F= mvf - mvi a = F
t m
1. A roller coaster car rapidly picks up speed as it rolls down a slope. As it starts down the slope, its velocity is 40 m/s. But 3 seconds later, at the bottom of the slope, its velocity is 105 m/s. What is the roller coaster’s average acceleration?
2. If a Jim Bob walks at a speed of .5 km/h for 15 seconds, how far will he travel? Your answer must be in meters.
3. A cyclist starts at rest and accelerates to 20 meters per second in three seconds. What is his acceleration?