# Forces and Newton's Laws

Student Learning Objectives
Lessons / Lecture Notes
Important Equations
Example Problems
Pencasts
Applets and Animations

Student Learning Objectives

• To understand and use Newton's 1st, 2nd, and 3rd laws.
• To recognize what does and does not constitute a force.
• To identify the specific forces acting on an object.
• To draw and make effective use of free body diagrams.
• To understand the connection between force and motion.
• To learn a strategy for solving force and motion problems.
• To identify action/reaction pairs of forces.
• To distinguish between mass, weight, and apparent weight.

Lessons / Lecture Notes

The Physics Classroom
(conceptual)

PY105 Notes from Boston University (algebra-based):

Introductory physics notes from University of Winnipeg (algebra-based):

HyperPhysics (calculus-based)

PHY2048 notes from Florida Atlantic University (calculus-based):

PHY2043 notes from Florida Atlantic University (calculus-based)

General Physics I notes from ETSU (calculus-based)

Important Equations

Example Problems

Problem 1
In the figure below, two forces, F1 and F2, pull a 50.0 kg crate. The magnitude of F1 is 215 N and it is applied at a 42.0o angle. The magnitude of F2 is 55.0 N. If the crate is accelerating to the right at a rate of 0.500 m/s2, find the coefficient of kinetic friction between the crate and the floor. (Solutions)

Problem 2
In the figure below, a block of weight w1 = 100.0 N on a frictionless inclined plane of angle 15o is connected by a cord over a massless, frictionless pulley to a second block of weight w2 = 30.0 N. (a) What are the magnitude and direction of the acceleration of each block?  (b) What is the tension in the cord? (Solutions)

Pencasts

Newton's Laws
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