Homeroom

Drop everything and read!

Homeroom

Use the textbook to define each of the following words and use each word in a sentence.AccelerationVelocity-Time GraphNewton’s Second Law

Warm-up

YouTube - Sid the Science Kid "Ignatz's Inertia"

Inertia Review: Newton’s First Law

The rate at which velocity changes with time is called acceleration

Acceleration is a measure of how quickly velocity is changing.

If velocity does not change, there is no acceleration.

Acceleration

We often refer to acceleration as speeding up BUT it really means any change in velocity.

Ex. A driver slowing down to stop at a light is accelerating.

What does acceleration mean?

Like velocity, acceleration is also a vector, which means it has both size and direction.

The direction of acceleration determines whether an object will slow down, speed up, or turn.

We can have:Acceleration in the same direction as motion=speed increasesAcceleration in the opposite direction of motion=speed decreases (negative acceleration)Acceleration at a right angle to motion=direction of motion changes

Acceleration is a Vector

To calculate acceleration, you need to know the starting velocity, the ending velocity, and the time interval which the object changed.

Acceleration= final velocity-initial velocity timeThe standard unit for acceleration is meters per second per second which is written as m/s2

Calculating Acceleration: All write in SIN Notes

Ama starts sliding with a velocity of 1 m/s. After 3s, her velocity is 7 m/s. What is Ama’s acceleration?

What do you know? Initial velocity=1m/s, final velocity=7m/s, time=3sWrite the formula: a= v(final)-(V)initial tSubstitute into the formula: a=7m/s-1m/s 3sCalculate: 6m/s = 2m/s2 3s

Let’s Practice

A man walking at 0.5 m/s accelerates to a velocity of 0.6m/s in 1s. What is his acceleration?Show each step and show work

You try!

A train traveling at 10m/s slows down to a complete stop in 20s. What is the acceleration of the train?Show each step and show work

You try!

Acceleration, like position and velocity, can change with time.

On a velocity-time graph:

1)A rising line on the velocity-time graph shows positive acceleration (speeding up)

2)A flat line shows no acceleration3)A falling line shows negative acceleration

(slowing down)

Velocity-Time Graphs

Newton’s Second Law of MotionThe acceleration of an object increases with increased force and decreases with increased mass.

IN SIMPLE TERMS: The harder you push, the further it goes. The more mass the object has, the harder it is to move it!

Newton’s 2nd law mathematically isForce= mass x acceleration or F=ma

*The standard unit for Force is a Newtons (N)*Mass is kilograms (kg)

Calculating Force

You have been given a worksheet. You are to work on the following problems in your Notebook. You must show all work for credit!! Remember your UnitsComplete #’s 7-13 14-16

**Please note Velocity and Speed are the same thing, except is a specific direction. The Units are the same for Speed and Velocity.

Independent Classwork 1st, 3rd PeriodDO NOT WRITE ON THE PAPER

http://www.youtube.com/watch?v=7VR6uG0EnoA

4th A & B Period

Complete all homework on a separate sheet of paper**You must show all work for Credit

Homework-All Classes