Motion

Frame of reference ______________________________________, a frame of reference is needed.

Relative Motion –_______________________________ ________________________________________________

Distance The length of a path between two points. Measured with the ________. Displacement ________________________________________________ __________________________________________________ _______________________– a quantity that as magnitude and direction. The magnitude can be size, length, or amount. Add displacements using vectors.

Displacement along a straight line.

Displacement that isn’t along a straight path Resultant vector – ____________________________________ Red line

Speed ______________________________________________ ________________________________________________ Measured in ____________ Ex: Speed of your car

________________– computed for the entire duration of the trip. Instantaneous speed – __________________________ ________________________________________________ Your car’s speedometer.

Graphing Motion ________________________to describe motion. Slope of a line on a distance-time graph is speed.

Car not at constant motion. Slope of straight portions = periods of constant speed.

Velocity A description of both ___________________________ ________________________________________________ Velocity is a vector.

Combining Velocities Two or more velocities add by vector ______________.

Acceleration ______________________________________________ Changes in speed, changes in direction, or changes in both.

Changes in Speed Acceleration – _________________________________ ________________________– car traveling at constant speed No longer pushed into seat. _______________________– acceleration that slows an object’s speed. Car coming to stoplight – pulled away from seat.

__________________________ The movement of an object toward Earth solely because of gravity. Objects falling near the Earth’s surface accelerate downward at a rate of _______________________

Changes in Direction You can accelerate even if your ___________________ Riding a bicycle around a curve. Your change in direction means you are accelerating.

Changes in Speed and Direction Example – roller coaster ride Car on windy road. Roller coaster physics clip.

Constant Acceleration ______________________________________________ Airplane’s acceleration at takeoff.

Calculating Acceleration You can calculate acceleration for straight-line motion by dividing the change in velocity by the total time.

Graphing Acceleration Speed-time graphs - _____________________________ ________________________________________________

Distance-time graph – ___________________________ ________________________________________________ Curve connects the data points that are plotted.

Instantaneous Acceleration _______________________________________________ ________________________________________________ Skateboarder on a half-pipe. At every moment she has an instantaneous acceleration, even if she is standing still and the acceleration vector is zero.