Negative 10 Miles per Hour? Speed and Velocity
Speed vs. Velocity • SPEED • Change in DISTANCEoccurring over TIME • MAGNITUDE ONLY • SCALAR • VELOCITY • Change in DISPLACEMENT occurring over TIME • MAGNITUDE and DIRECTION • VECTOR
Velocity & Average Velocity DIRECTION MATTERS!!! Which equation does this remind you of? SLOPE OF A GRAPH!
Example #1 • Tom gets on his bike at 12:00 in the afternoon and begins riding west. At 12:30 he has ridden 8 miles. • Calculate his velocity • Convert to meters per second
Total Distance Traveled Total Time for the Trip Average Speed OR NOT IN YOUR RT!!! Can only be a POSITIVE quantity!
Example #2 • Sally gets up one morning and decides to take a three mile walk. She completes the first mile in 8.3 minutes, the second mile in 8.9 minutes, and the third mile in 9.2 minutes. • Calculate her average speed during her walk • Convert her speed to meters per second
A car travels around a corner by traveling 50 meters east, then 50 meters north. It makes the trip in 50 seconds. Calculate the car’s average SPEED Distance = ? Distance = 100m Total time = 50s
A car travels around a corner by traveling 50 meters east, then 50 meters north. It makes the trip in 50 seconds. Calculate the car’s average VELOCITY Displacement = ? Displacement = 70.7m Time = 50s
SUMMARY • Speed vs. Velocity • Which is a scalar/vector? • Definition? • Units? • Velocity Equation • Average Velocity Equation • Average Speed Equation*