Motion

Motion

• Motion- the change in the position of an object with respect to time and its reference point

• Motion is RELATIVE

• Reference point/ frame of reference: a point/object that is not moving

Reference Point and Relative Motion

Example:- If you are sitting on a train looking at your

neighbor, neither of you seem to be moving- If you look out the window at people standing

on the side, they seem to be moving backwards

- If the people on the side are looking at you, you seem to be moving forward

Describing Motion

• Distance- the length between two points–Units: meters, kilometers, etc.

• Time

Speed

• Speed- is the distance traveled per unit of time–Units: m/s, km/s, etc.

S= speedD = distancet= time

Solve for other variables:

D= s*t t= D/s

Formula:S = D/t

Average Speed

• The total distance divided by the total time

Instantaneous Speed

• The speed at any given instant

You must always show your work and units!!

ALWAYS METRICS

No answer is complete without units!

Let’s try one!

Calculate the speed of a dog running through a field if he is covering 23.7 meters in 54 seconds.

Given: Formula:

Find: Work Space:

If a cross country runner covers a distance of 347 meters in 134 seconds what is her speed?

Given: Formula:

Find: Work Space:

Velocity

Velocity- The speed and direction an object is moving in

Units: speed and a direction

Example: The car’s velocity is 60 km/hr EAST

Try This:

Calculate the velocity of a dog running north through a field if he is covering 23.7 meters in 54 seconds.

Given: Formula:

Find: Work Space: