+Warm-up/Journal

Warm-up: Draw a FBD to represent yourself riding in a car.

Journal: For Christmas I would love to get…

+

Newton’s Second Law

+Objectives

To be able to state and explain Newton’s Second Law of Motion

To be able to apply Newton’s Second Law of Motion to physical situations

+Evidence

A change in motion, or an acceleration is evidence of a force.

+Relationship

“The acceleration of an object is directly proportional to the

net force acting on it and inversely proportional to its mass. The direction of the

acceleration is in the direction of the applied net force.”

+Newton’s Second Law

Fnet = maUnits (kg m/s2 or N)

+What this says

If the net force is equal to zero, so too is the acceleration.

If the Net force does not equal zero, then the acceleration is also not zero, and is in the direction of the applied net force.

+Magnitude

If I have a book of mass 5 kg free falling with g=-10

If I have two books of mass 5kg stacked on top of each other falling with g=-10

+Example #1

How much force is needed by a the driver of an Formula 1 car that ran out of gas to push the 700 kg car with and acceleration of 0.05 m/s2?

+Example #2

What is the acceleration of a 2kg brick thrown with a force of 4 Newtons?

+Example 3

Jack has an engine that can provide a force of 5.6 newtons. He wants to place the engine on a cart so it accelerates at 3.5m/s2. What should the combined mass of the cart and engine be to achieve this acceleration?

+F=ma Challenge

The group to complete the F=ma worksheet in the fastest time with all of the correct answers (including units) will receive a Bonus Point