Sci. 1-1 Measuring Motion Pages 4-10

A. Reference point- an object that appears to stay in the same place Examples- buildings, trees, mountains

B. Motion- when an object changes position over time when compared with a reference point.

Speed = Distance time S= D t C. Speed depends on the distance traveled and the time taken to travel that distance Speed = Distance time S= D t

D. Velocity- the speed of an object in a particular direction

E. Velocity always includes a reference direction- north, south, east, west, NW, NE, SW, SE

F. Velocity changes every time the speed changes or if the direction changes.

When you combine two velocities that are in the same direction, add them together to find the resultant velocity. 15 m/s east + 1 m/s east = 16 m/s east

When you combine two velocities that are in opposite directions, subtract the smaller velocity from the larger velocity to find the resultant velocity. 15 m/s east – 1 m/s west = 14 m/s east

I. Acceleration- to change velocity, (to change speed or direction or both)

a = fv-sv t J. Acceleration = final velocity-starting velocity time it takes to change velocity a = fv-sv t

Increase in velocity= positive acceleration Decrease in velocity= negative acceleration or deceleration

L. Centripetal acceleration- traveling in a circular motion L. Centripetal acceleration- traveling in a circular motion. You are constantly changing directions as you go around the circle