Distance Vs. Displacement

• Distance: is how far point A is from point B• Displacement: is the distance and direction

between starting and ending positions. (Has a direction)

• Example: The distance between New Castle and Muncie is 22.7 Miles. However the Displacement of Muncie from New Castle is 22.7 Miles North.

Relative Motion

• Something in motion changes its position.• However, The position of an object is

described relative to a reference point (which could be another object)

Relative Motion Example• Example:

– Dash stands by Syndrome and then runs past him to quickly get away from a ray blast. If Syndrome is the reference point then Dash has been in motion.

Reference Point

ZAP

Speed

• Speed- is the distance traveled divided by the time need to travel the distance

• Measured in meters/second

Equation:Speed= Distance / Time

Speed Example:

• Superman is faster than a speeding bullet. If he travels 1000 meters in 3 seconds what is his speed?

• Equation: Speed = Distance/ Time– Speed = ? m/s– Distance= 1000 meters– Time = 3 Seconds

Speed= 335.28 m / s

Types of Speed

• Constant Speed- is a speed that doesn’t change. So driving a 50 mph and not increasing or decreasing speed.

• Changing Speed:– Average Speed: This is an average speed for a

distance, but does not tell you what your speed is an any specific instance (point in time)

– Instantaneous Speed: This is the speed at a specific instance(point in time)

• Example: Car Speedometer

Velocity• Velocity: is displacement divided by time

• Velocity is very similar to speed with a direction attached

• Example: 2 m/s due East

Interesting fact:

Usain Bolt: has clocked nearly 28 mph in the 100-meter sprint.

Acceleration• Acceleration: is the change in velocity divided by the

amount of time required for the change to occur.• Includes direction.• Speeding up: is positive acceleration• Slowing down: is negative acceleration (decelerating) or

could be worded accelerating in the opposite direction.

Any change in direction is also ACCELERATION!

Acceleration Example

• Acceleration= ? m/s• Velocity Initial= 0 m/s• Velocity Final= 80 m/s• Time 1= 0 seconds• Time 2 = 10 seconds

• A= (80m/s – 0m/s) / (10s – 0s)

• A= 8 m/s2Vf Stands for final velocity (ending)

Vi Stands for initial velocity (beginning)

After Note Quiz

1. What is the difference between instantaneous speed and average speed

2. What is the difference between distance and displacement?

3. What is the formula for acceleration

Get out a half sheet of paper and answer these questions, make sure to number them, put your name in the upper right hand corner. YOU MAY USE YOUR NOTES