Motion

What is motion? When an object’s distance changes relative to a reference point.

What is a reference point? An object used for comparison to see if something is in motion!

So….How do you know that you are moving? It depends on how you look at things. You can use different reference points to justify the motion of the same object. Look at the books on your table. Are they moving? Use the floor as a reference point. What if the sun is your reference point?

Create your own example!!! More examples…. Explain how the illustrations are examples of motion and no motion. Create your own example!!!

What is speed? The distance traveled divided by the time taken to travel that distance

DISTANCE mm, cm, m TIME sec, min, hours SPEED m/sec, km/hr

Units for Speed…. Units for speed will be unit of distance over a unit of time (miles per hour or meters per second) Units for distance are (millimeters, centimeters, kilometers etc.) Units for time will be (seconds, minutes, hours etc.)

Practice 1. If a horse runs 21 m in 3 seconds, what is its speed? Answer: distance = 21m = 7m/sec time = 3sec 2. If a cyclist travels 32 km in 2 hours, what is the cyclists average speed? Distance = 32km Time = 2 hrs Speed = 32km = 16 km/hr. 2hrs.

SPEED IN A GIVEN DIRECTION! WHAT IS VELOCITY? SPEED IN A GIVEN DIRECTION! Example: The Atlanta Falcons are traveling to Miami to play the Dolphins. The team bus travels at 90km/hr. What is the velocity of the bus?

WHAT IS ACCELERATION? When an object does ANY of the following, it is called acceleration… Speeds up Slows Down (deceleration) Changes Direction

How can we describe motion on a graph?

Interpret The Graph Below: The graph shows an object which is not moving (at rest). The distance stays the same as time goes by because it is not moving.

Interpret The Graph Below: The graph shows that the objects distance increases as time passes. The object is moving and so it has velocity. The straight line shows it is constant (not changing).

Interpret The Graph Below: Just like the previous graph, this graph shows an object moving with constant velocity

Interpret The Graph Below: The curve in the graph shows that the objects velocity is changing as time passes. This is acceleration

Interpret The Graph Below: In the first part of the graph the object is moving with constant velocity. In the second part of the graph the object is at rest (not moving). In the third part the object is again moving with constant velocity

Interpret The Graph Below: The graph shows that the objects velocity does not change as time passes. It shows constant velocity.

Interpret The Graph Below: The graph shows that the objects velocity is increasing as time passes – it is accelerating. The straight line shows that it is constant acceleration