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Ch. 11 Sec. 2. Speed & Velocity. Speed. Ratio of the distance traveled in an amount of time Speed = distance/time Units: km/hr, m/sec. Speed. Average Speed Total distance traveled divided by the time Velocity (v) = Distance (d)/Time (t) Instantaneous Speed
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Ch. 11 Sec. 2 Speed & Velocity
Speed • Ratio of the distance traveled in an amount of time • Speed = distance/time • Units: km/hr, m/sec.
Speed • Average Speed • Total distance traveled divided by the time • Velocity (v) = Distance (d)/Time (t) • Instantaneous Speed • Rate at which an object is moving @ given moment • Car Speedometer
Speed Problems What is the speed of a cyclist who travels 50 meters in 25 seconds? S = d/t 50 m/25 s 2 m/s You are in a car traveling an average speed of 60 km/hr. The total trip is 240 km. How long does the trip take? t = d/s 240 km/60 km/hr 4 hrs.
Motion • Represented by a distance-time graph. • The slope is the speed
Velocity • Speed in a given direction. • Uses: Navigation (airplanes, ships), weather, etc. • Vector quantity – represented graphically by arrows ( ). • Length = magnitude • Arrowhead = direction
Velocity Problem • If you row a boat upstream at 10 km/hr and the river has a downstream velocity of 5 km/hr, you are actually moving at what velocity? = 5 km/hr downstream 10 km/hr upstream 5 km/hr upstream
Problem • A person runs a 100.0 meter dash is 11.8 seconds, what is the velocity?
Velocity • Speed and Velocity Lab