The Moving Man: Distance, Displacement, Speed and Velocity

DISTANCE & DISPLACEMENT
Distance from reference point (in meters): 
House
8 meters
Tree
8 meters
Wall
10 meters

Displacement from reference point (in meters):
House
8 meters
Tree
-8 meters
Wall
10 meters

What is the difference between an object’s distance and its displacement?

An objects displacement must include a direction (a +,- sign can indicate a direction). The distance is always positive because it is the absolute value (the direction is not included) from the reference point. 


SPEED & VELOCITY

What is the difference between an object’s speed and its velocity?

An objects speed is how fast it is going in an amount of time. An objects velocity is the amount that the objects displacement has changed in the amount of time.

The unit of distance in the moving man is meters.

The unit of time used in the moving man is seconds.
After watching the moving man move at a velocity of 1 meter/sec and at a velocity of 4 meters/sec I observed that he moved faster at 4 meters/sec.
When I let the man move at a velocity of 1 meter/sec for two sec. he went 2 meters. When I let him move at a velocity of 4 meters/sec for two sec. he had moved about 8 meters. He covered more distance at 4 meters/sec.
You can calculate the velocity by dividing the meters by the seconds.

TRIAL #1    2 meters divided by 2 sec = 1 m/sec

TRIAL#2    8 meters divided by  2 = 4 m/sec

A man moving at a slow and steady pace in a + direction

A man moving at a quick pace in a + direction

A man standing still at 4 meters

A man moving from 0m to 10m at a steady fast pace, pausing, and then moving back to 0 m at a steady slow pace.

A man moving from 0 to 10 meters at an ever-increasing speed 

A man moving from 10m to 0m at a steady fast pace

A man moving at a slow and steady pace from 10 back to 0

A straight line represents a constant speed while a curved line represents acceleration or deceleration. 

The shape of the line on a graph must be an upward curve to represent acceleration. 

A flat line represents a constant steady pace. A sloping line represents acceleration or deceleration.   If the line on a graph is steep it means the object is moving very quickly. 

Why is the line sloping upward to the right between the 2^nd & 3^rd second, but downward to the right between 6^th and the 15^th seconds?

The man was moving quickly in a positive direction and then he started to head back to were he began at a much slower pace.

He stopped between the 3rd and 6th seconds and between the 16 and 20 second marks.