Measuring Motion Chapter 1 Section 1

Warm Up:

Write in your notebooks. Describe your position in the classroom. Be specific, use reference points and a set of reference directions.

Objectives: Nov. 28th, 2016

SWBAT: ● Describe motion of an object by the position of an object in relation to a reference point. ● Identify two factors that determine speed. ● Explain the difference between speed and velocity. Homework:

Observing Motion

While watching the video (10 min.) Define: Reference Point Speed - (Equation) Velocity Why can’t we feel the Earth moving? How do graphs with velocity work?

Observing Motion

motion→ object changing position over time relative to a reference point

Reference point: an object that appears to stay in place

Common Reference Points

You can use both moving objects and non-moving objects as reference poınts? The Earth is a common reference point

Warm Up:

What is your average speed if you jog for 0.5 hr and travel 4,000 m?

4,000 m / 0.5 hr = 8,000 m/hr

Objectives: Nov. 29th, 2016

SWBAT: ● Explain the difference between speed and velocity. ● Solve problems involving speed and velocity

Homework: Pg 9, 1-7

Speed-- Distance and Time

speed→ the distance traveled dıvıded by the time interval during which the motion occurred

SI unit for speed is meters/second Or m/s

Some other units are:

km/s ft/s km/hr

Average speed Average speed is used because many objects do not move at the constant rate Use the calculation below:

Example You and your family are driving to Disney World which is about 1,010 miles. You and your family finally arrive about 15 hours later. During your road trip you took many pit stops along the way. Calculate the average speed your famıly drove throughout the trıp. What are we looking for? What equation do we need? What are we given?

Example You and your family are driving to Disney World which is about 1,010 miles. You and your family finally arrive about 15 hours later. During your road trip you took many pit stops along the way. Calculate the average speed your famıly drove throughout the trıp. Average speed= ? Distance travelled= 1,010 miles Total time= 15 hours

Average speed= 1,010 miles / 15 hours Average speed= 67.3 miles per hour

Velocity velocity→ the speed of an object in a particular direction What is the difference between velocity and speed? Velocity must include a particular direction

Changing Velocity The velocity is constant only if its speed and direction DO NOT change

● Constant velocity is always motion along a

straight line

Velocity will change when either speed or direction will change

Changing Velocity What are two ways that velocity can change?

Changing speed

Changing direction

Combing Velocities When you combine 2 velocities that are in the same direction you add them together to find the resultant velocity 1st velocity (same direction) + 2nd velocity (same direction) = resultant velocity

Combing Velocities When you combine 2 velocities that are in the opposite direction you subtract the smaller velocity from the larger velocity to get the resultant velocity ● The direction of the velocity will be in the direction of the larger velocity

Larger velocity - smaller velocity = resultant velocity

Warm Up: A plane traveled 150 minutes covering 1200 miles. What is the plane's speed in miles per hour? 150 minutes = 2.5 hrs Speed = distance / time Speed = 1200 mi / 2.5 hr = 480 miles per hour

Objectives: Nov. 30th, 2016

SWBAT: ● Defıne and ıdentıfy examples of acceleration ● Relate velocity and acceleration ● Solve problems involving average acceleration

Homework: Pg 9, 8-11

Acceleration acceleration→ the rate at which velocıty changes over tıme An object will accelerate if its: ● Speed ● Direction Or both change

Acceleration Positive acc. → increase in velocity Negative acc.

→ decrease in v. The faster the velocity changes, the greater the acceleration

Average Acceleration Just like average speed, you can calculate average acceleration! Calculate average acceleration using the equation below:

Average Acceleration

Average acceleration= final velocity - starting velocity time it takes to change velocity

Example A plane passes over point A at a velocity of 240 m/s north. Forty seconds later it passes over point B at a velocity of 260 m/s north. What ıs the plane’s average acceleratıon? Step 1: What are we looking for? Step 2: What are we given?

Step 3: What equation do we need? Solve.

Example A plane passes over point A at a velocity of 240 m/s north. Forty seconds later it passes over point B at a velocity of 260 m/s north. What ıs the plane’s average acceleratıon? Average acceleration= ? Starting velocity= 240 m/s Final velocity= 260 m/s Time= 40 seconds

Avg a = final v - start v time Avg a = (260 m/s - 240 m/s) 40 s

Example

Average acc. = 260 m/s - 240 m/s 40 seconds Avg a = 20 m/s 40 s Average acceleration = 0.5 m/s North 2

Think it through... The Earth is traveling in a circular motion, orbiting the sun. Does the Earth experience acceleration or is it a constant speed?

Explain your reasoning.

Centripetal Acceleration The Earth is traveling in a circular motion and is always changing its direction. This means the velocity is always is always changing. This also means it is accelerating Acceleration that occurs in circular motion is known as centripetal acceleration

Objectives: Nov. 30th, 2016

SWBAT: ● Defıne and ıdentıfy examples of acceleration ● Relate velocity and acceleration ● Solve problems involving average acceleration

Homework: Pg 9, 8-11