DAY 28

#Goals: SWBAT...

1. Draw correct FBD's, with appropriate vector magnitude and direction.

2. Support classmates with helpful tutoring

3. Use FBD's to find Net Force

4. Describe the relationship between mass, net force, and acceleration

Warm-Up (4min)

Copy and fill in (or choose) the correct answers for the following:

• 1. Complete the FBD on the board
• 2. Which requires more force to accelerate? Desk or Chair? Why?
• 3. If you apply the same force to a bike, and to a train locomotive, which will accelerate faster? Why?

CLASSWORK

1. #028A: Newton's 2nd Law

Notes:

• Newton's second law of motion pertains to the behavior of objects for which all existing forces are not balanced.
• The second law states that the acceleration of an object is dependent upon two variables - the net force acting upon the object and the mass of the object.
• The acceleration of an object depends (directly/inversely) upon the net force acting upon the object, and (directly/inversely) upon the mass of the object.
• As the force acting upon an object is increased, the acceleration of the object is (increased/decreased).
• As the mass of an object is increased, the acceleration of the object is (increased/decreased).

2. #028B: Practice with the 2nd Law

A. Complete the chart on the board. You should be able to find one pattern for each of the three sections

B. Complete the following:

1. Determine the accelerations that result when a 12-N net force is applied to a 3-kg object and then to a 6-kg object.

2. A net force of 15 N is exerted on an encyclopedia to cause it to accelerate at a rate of 5 m/s2. Determine the mass of the encyclopedia.

3. Suppose that a sled is accelerating at a rate of 2 m/s2. If the net force is tripled and the mass is doubled, then what is the new acceleration of the sled?

4. Suppose that a sled is accelerating at a rate of 2 m/s2. If the net force is tripled and the mass is halved, then what is the new acceleration of the sled?

Need help? Click below...scroll down until you see the problems, then click the "see answer link"

At Home Learning (HW)

1. Quiz Friday on FBD's. review the following... Day 26 A, B, C and Day 27 A, B

2. #028C: Your homework, due Friday, is to prepare for class by watching 5 minutes worth of video. You should understand how to solve net force problems after watching the video

Take Notes: A Basic Newton's Second Law Problem

Watch the video, and answer the EdPuzzle Questions: EDpuzzle

NGSS Standard (this is what we're learning with this unit)

Analyze data to support the claim that Newton’s second law of motion describes the mathematical relationship amongthe net force on a macroscopic object, its mass, and its acceleration. [Clarification Statement: Examples of data could include tables or graphs of position or velocity as a function of time for objects subject to a net unbalanced force, such as a falling object, an object sliding down a ramp, or a moving object being pulled by a constant force.] [Assessment Boundary: Assessment is limited to one-dimensional motion and to macroscopic objects moving at non-relativistic speeds.]