Mr. Bouyer

Day 1 | Day 2 | Day 3 | Lab | Vocabulary Test

Acceleration Negative acceleration	Centripetal acceleration	Deceleration Centrifugal force

Acceleration: The rate of change in velocity.

At what rate does gravity accelerate falling objects?

To calculate acceleration, use the equation:

Acceleration = (Final Velocity) - (Original Velocity) / Time A = Vf - Vo / t

 

Acceleration Practice Problem: A car going 50mph accelerates to pass a truck. Five seconds later the car is going 80mph. Calculate the acceleration of the car.

Racing Engineer

Deceleration: A term commonly used to mean a decrease in speed. Acceleration in a direction opposite to the direction of travel. Deceleration is negative acceleration and has a negative value to indicate direction.

Experimentwith speed and acceleration.

Test Your Concept Understanding: The christmas tree light turns green and 4.5 seconds later a top fuel dragster is traveling 300 miles per hour. Calculate the acceleration of the dragster. The christmas tree light turns green and 6 seconds later an alcohol dragster is traveling 250 miles per hour. Calculate the acceleration of the dragster. You are driving down the road at 65 miles per hour when you appy the brakes to avoid an accident. Ten seconds later you have brought the car to a stop. What was your acceleration?

Day 2

A graph of acceleration always has what shape?

Distance - Time Graph for Acceleration:

See a graph of acceleration.
Experiment with acceleration graphs.

 

Homework Assignment 202:
This assignment must be turned in by the beginning of class tomorrow to receive credit.

1. Use Excel to make a Distance/Time graph of this acceleration data.
2. Use the appropriate evaluation rubric to evaluate your graph before turning it in.

Day 3

The Earth is accelerating toward what object?

Centripetal Acceleration: Acceleration toward the center of a circular path.

An object traveling in a circle is accelerating toward the center of the circle.

For an object to move in a circular path, some force must be accelerating it toward the center of the circle. While this force may not be obvious, it is there. Notice what happens to the object when the accelerating force is removed.

What happenswhen things spin?

Centrifugal Force An apparent force that appears only in rotating frames of reference.

Test Your Concept Understanding: A car is traveling down the highway at a constant velocity. Using centripetal acceleration, describe what happens when the steering wheel is turned? Use the centrifugal force website above to answer the next two questions: A car goes into a sharp left-hand curve at a high rate of speed. Does the passenger in the car move against the car door, or does the car door move against the passenger? What have you learned about circular motion that caused you to answer the way you did?

With your table, ask your facilitator for a one-hole rubber stopper and a one meter length of string. Tie the string through the hole in the stopper and, standing in a clear space, swing the string in a flat circle over your head. Answer the following questions about the actions of the stopper. Describe what the stopper is doing. What provides the acceleration to the stopper? What happens if you release the string while swinging it around? Why does this happen?

Physical Science

Answer to acceleration problem:
A = V_f - V_o / t
A = 80mph - 50mph / 5sec
A = 6 miles per hour per second

Answer to deceleration problem:
A = V_f - V_o / t
A = 50ft/s - 200ft/s / 5s
A = -150 ft/s/s

Gravity accelerates objects near the surface of the Earth at a rate of 9.8 m/s².
This means that for every second an object falls, its speed increases by 9.8 m/s.

A graph of acceleration is always a curve.

The earth orbits the sun. This means the earth is accelerating toward the sun.