Chapter 2Physics A First Course Forces and Motion

Forces and MotionLaws of Motion

2.1 Newton's First Law2.2 Acceleration and Newton's Second Law2.3 Gravity and Free Fall2.4 Graphs of Motion

2A Investigation: Law of Inertia

Key Question:

Why are heavier objects harder to start or stop moving?

*Students read text section 2.1AFTER Investigation 2A

2A Investigation Topics Launch cars of different mass. Measure time intervals. Calculate speed based on measured time intervals. Graph speed vs. mass. Research and define terms: inertia, weight and mass.

Chapter 2.1 Objectives and Vocabulary

force Newton's first law inertia newton net force

Recognize that force is needed to change an object's motion.

Explain Newton's first law.

Describe how inertia and mass are related.

2B Investigation: Newton's Second Law

Key Questions:

What is force?

What is the relationship between force and motion?

*Students read text section 2.2AFTER Investigation 2B

2B Investigation Topics

Measure time intervals of car moving along track. Calculate and compare speeds of car at different

points on track. Evaluate forces acting on car. Calculate acceleration of car. Use Newton's second law to calculate the force. Graph force vs. time for the car on the track. Explain how speed and acceleration are different

using graphs.

Chapter 2.2 Objectives and Vocabulary acceleration

deceleration Newton's

second law

Define and calculate acceleration.

Explain the relationship between force, mass, and acceleration.

Determine mass, acceleration and force given two of the quantities.

Chapter 2.3 Objectives and Vocabulary free fall

acceleration due to gravity

velocity weight air resistance terminal speed

Describe the motion of an object in free fall.

Calculate the speed and distance for an object in free fall.

Distinguish between mass and weight.

Explain how air resistance affects the motion of objects.

Chapter 2.4 Objectives and Vocabulary slope Describe motion with position

versus time and speed versus time graphs.

Use a position versus time graph to calculate speed from the slope.

Use a speed versus time graph to calculate acceleration and distance traveled.