Distance, Speed, Motion, velocity, Ch. 11 & 12 Notes

Distance vs Displacement Distance- the length of a path between two points. Displacement- direction and the length of a straight line from the starting point to the ending point.

Motion Motion- A change in position with respect to a frame of reference. Frame of reference: nonmoving point from which motion is measured Reference point Motion

Speed Speed - distance traveled per unit time Speed is the rate of motion Rate- anything that happens over time Units for speed: mi/hr, km/hr, m/s, m/min

Speed - practice  Florence Griffith Joyner set a world record by running m in 21.3 seconds. What was her speed?  Suppose polar bears were running on land instead of swimming. If the polar bear runs at a speed of about 8.30 m/s, how far will it travel in s? Put your answer in scientific notation.  How much time does it take for a bird flying at at speed of 45 km/hr to travel a distance of 1800 km?

More Speed stuff Instantaneous Speed - speed at a given instant Constant speed – speed that stays the same over time Average Speed- total distance traveled over total time it took to travel that distance. Add up all the distances, add up all the times. Plug into the speed equation.

Average Speed - practice  You drive miles in 3.00 hours. Then you stop at a rest stop for Wendy’s and to gas up the car. After your stop you travel miles in 1.50 hours. What is your average speed for the entire trip?

Velocity Velocity  speed in a given direction  can change even when the speed is constant Resultant velocity – when velocities are combined  EX: bus moving at a velocity of 15 mi/hr, North  You on the bus walking, your velocity is 1 mi/ hr N  Resultant velocity = 16 mi/hr  You on the bus walking again, but this time you’re walking in opposite direction the bus is going- your velocity is -1 mi/hr South  Resultant velocity = 14 mi/hr

Velocity- practice If Justin races his Chevy S-10 north bound on Highway 235 for meters in 60.0 seconds. What is Justin’s velocity?

Graphing Motion slope = steeper slope = straight line = flat line = Distance-Time Graph A B faster speed constant speed no motion speed 80c6-4ec b3/kinematics