Calculating Velocity Honors Physics

Speed Speed is a scalar quantity that refers to "how fast an object is moving.“ Speed can be thought of as the rate at which an object covers distance.

Velocity Velocity is a vector quantity that refers to "the rate at which an object changes its position." Velocity is a vector quantity. As such, velocity is direction aware.

Velocity (cont.) When evaluating the velocity of an object, one must keep track of direction. It would not be enough to say that an object has a velocity of 55 mi/hr. One must include direction information in order to fully describe the velocity of the object.

Calculating Average Speed 𝑎𝑣𝑒𝑟𝑎𝑔𝑒 𝑠𝑝𝑒𝑒𝑑= 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 𝑡𝑟𝑎𝑣𝑒𝑙𝑒𝑑 𝑡𝑖𝑚𝑒

How far did the skier travel in each leg of his journey? Average speed example How far did the skier travel in each leg of his journey?

Average speed example Leg A to B  180 m Leg B to C  140 m Leg C to D  100 m Total distance traveled  420 m Total time taken  3 min 𝑎𝑣𝑒𝑟𝑎𝑔𝑒 𝑠𝑝𝑒𝑒𝑑= 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 𝑡𝑟𝑎𝑣𝑒𝑙𝑒𝑑 𝑡𝑖𝑚𝑒 = 420 𝑚 3 𝑚𝑖𝑛 =140 𝑚/𝑚𝑖𝑛

Calculating average velocity 𝑎𝑣𝑒𝑟𝑎𝑔𝑒 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦= 𝑑 𝑓 − 𝑑 𝑖 𝑡 𝑓 − 𝑡 𝑖

Average velocity example Total displacement  140 m to the right Total time taken  3 min 𝑎𝑣𝑒𝑟𝑎𝑔𝑒 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦= 𝑑 𝑓 − 𝑑 𝑖 𝑡 𝑓 − 𝑡 𝑖 = 140 𝑚 3 𝑚𝑖𝑛 =46.7 𝑚/ min 𝑡𝑜 𝑡ℎ𝑒 𝑟𝑖𝑔ℎ𝑡!

Do this one with your table Group (LS) The physics teacher walks 4 meters East, 2 meters South, 4 meters West, and finally 2 meters North. The entire motion lasted for 24 seconds. Determine the average speed and the average velocity.

Do this one with by yourself (LS) Calculate both the average speed and the average velocity.

Do this one with by yourself (LS) A student walks 17 meters north in 3 seconds, pauses for 1 seconds, and then turns around and walks 5 meters back south in 2 seconds. What was the student’s average speed? What was their average velocity? Draw a picture if it helps!