Chapter 5 Physics A First Course Energy and Systems
Jan 11, 2016
Chapter 5Physics A First Course Energy and Systems
Energy and SystemsForces in Equilibrium
5.1 The Force Vector
5.2 Forces and Equilibrium
5.3 Friction
5.4 Torque and Rotational Equilibrium
5A Investigation: Equilibrium and Forces
Key Question:
What can we say about forces when nothing is moving?
*Students read text section 5.1
AFTER Investigation 5A
5A Investigation Topics
Use spring scales.
Make an object in equilibrium.
Measure forces on an object that is in equilibrium.
Draw free-body diagrams.
Measure the force of gravity.
Distinguish between weight and mass.
Chapter 5.1 Objectives and Vocabulary
scalar magnitude vector component free-body diagram
Draw vectors to scale to represent a quantity's magnitude and direction.
Solve vector problems.
Find a vector's components.
5.1 Pythagorean Theory
a2 + b2 = c2
side b
hypotenuse, side c
side a
Chapter 5.2 Objectives and Vocabulary equilibrium
normal force resultant Hooke's lab spring constant
Explain what it means to say an object is in equilibrium.
Use free-body diagrams to find unknown forces.
Explain how springs exert forces.
Add force vectors.
5B Investigation: Friction
Key Question:
How do we account for friction?
*Students read text section 5.3
AFTER Investigation 5B
5B Investigation Topics
Measure kinetic energy of a system. Determine the force of friction from experimental
data. Compare friction in a car to friction in a sled. Use Newton's second law to calculate force of
friction in a rolling car. Compare the strength of sliding friction to that of
rolling friction. Determine how the force of friction varies with
speed.
Chapter 5.3 Objectives and Vocabulary friction
sliding friction static friction lubricant
Distinguish between sliding and static friction.
Explain the cause of friction.
Discuss reasons to increase or decrease friction.
Chapter 5.4 Objectives and Vocabulary torque
rotate axis of rotation line of action lever arm rotational
equilibrium
Explain how torque is created.
Calculate the torque on an object.
Define rotational equilibrium.