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Homeroom. Drop everything and read!. Warm-up. Use the textbook to define each of the following words and use each word in a sentence. Acceleration Velocity-Time Graph Newton’s Second Law. Inertia Review: Newton’s First Law. YouTube - Sid the Science Kid " Ignatz's Inertia". Acceleration.
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Homeroom Drop everything and read!
Warm-up • Use the textbook to define each of the following words and use each word in a sentence. • Acceleration • Velocity-Time Graph • Newton’s Second Law
Inertia Review: Newton’s First Law • YouTube - Sid the Science Kid "Ignatz's Inertia"
Acceleration • 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.
What does acceleration mean? • 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.
Acceleration is a Vector • 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 increases • Acceleration in the opposite direction of motion=speed decreases (negative acceleration) • Acceleration at a right angle to motion=direction of motion changes
Calculating Acceleration: All write in SIN Notes • 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 • time • The standard unit for acceleration is meters per second per second which is written as m/s2
Let’s Practice • 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=3s • Write the formula: a= v(final)-(V)initial • t • Substitute into the formula: a=7m/s-1m/s • 3s • Calculate: 6m/s = 2m/s2 • 3s
You try! • 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
Velocity-Time Graphs • Acceleration, like position and velocity, can change with time. • On a velocity-time graph: • A rising line on the velocity-time graph shows positive acceleration (speeding up) • A flat line shows no acceleration • A falling line shows negative acceleration (slowing down)
Newton’s Second Law of Motion • The 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!
Calculating Force • Newton’s 2nd law mathematically is • Force= mass x acceleration or F=ma • *The standard unit for Force is a Newtons (N) • *Mass is kilograms (kg)
Independent Classwork 1st,3rdPeriodDO NOT WRITE ON THE PAPER • 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 Units • Complete #’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.
4th A & B Period • http://www.youtube.com/watch?v=7VR6uG0EnoA
Homework-All Classes • Complete all homework on a separate sheet of paper • **You must show all work for Credit