Chapter 11 Motion

Chapter 11 FRAME OF REFERENCE

http://www. visualnews http://www.visualnews.com/2014/11/09/carsten-hollers-upside-mushroom-room-turns-world-upside/ https://www.niagarafallsmarriott.com/attractions/upside-down-house Who is upside-down? http://busan.for91days.com/2012/06/28/busans-trick-eye-museum/

https://www.niagarafallsmarriott.com/attractions/upside-down-house http://www.visualnews.com/2014/11/09/carsten-hollers-upside-mushroom-room-turns-world-upside/ Who is upside-down? http://busan.for91days.com/2012/06/28/busans-trick-eye-museum/

Motion Motion is a change in location (you’re moving) Relative Motion: Right now you are all sitting still. Are you still moving? Can you ever stop moving?

Motion Motion is Relative: Relative to the Sun you are traveling 100,000 km/hr (62,137 mph)

Motion is Relative You are sitting on a bus with a pencil over your head, traveling at 50 miles per hour Relative to the bus, what is the pencil’s speed? Relative to the road, what is the pencil’s speed? Drop the pencil. Relative to the road what is the speed of the pencil? This means the pencil will land (behind you, in front of you, behind you)?

Distance/Displacement http://villains.wikia.com/wiki/Vector_Perkins Distance: measurement of length between two points (no direction) Since it has no direction it’s a scalar quantity How far it’s traveled Displacement: change in original position (direction) Since it has direction it’s a vector quantity A vector has both direction and magnitude (size)

Distance/Displacement Example 0 Miles 50 Miles 30 Miles South Distance: Car traveled 50 miles, then backed up 30 miles 50mi + 30mi = 80 miles Displacement: Car traveled 50 miles, then backed up 30 miles 30mi (from original position)

Distance/Displacement Example Distance: Runner runs around the 400m track. Displacement: 0m because he’s right were he started

Distance/Displacement Example

Speed/Velocity Speed is how fast an object is moving Velocity It is a scalar quantity Since it’s a scalar quantity it has only magnitude (size) Units are m/s Velocity It is a vector quantity It has magnitude (size) and direction If either the speed or the direction changes, the velocity changes

Average Speed/ Instantaneous Speed Instantaneous Speed: is the speed at any given second (when you check your speedometer) Average Speed: is the calculation of Distance/Time

Acceleration Acceleration is a vector quantity (magnitude/direction) that is defined as the rate of which an object changes it’s speed. An object is accelerating if it’s speed or direction is changing Units are m/s2 To calculate acceleration: A= change in velocity time

Acceleration On a circular track a car is keeping constant speed, but the velocity is always changing. Why?