Presentation on theme: "Aim: How can we calculate average velocity when distance is unknown? Do Now: What is the average velocity between A and B? Velocity (m/s) Time (s) 20 60."— Presentation transcript:
Aim: How can we calculate average velocity when distance is unknown? Do Now: What is the average velocity between A and B? Velocity (m/s) Time (s) A B
Solve for Δd Substitute the new formula for velocity into this formula This is a derived formula and is not on the reference tables!
Word problems 1.The initial velocity of a car is 7.5 m/s and it steadily increases to a final velocity of 22.5 m/s in 8 s. What is the average velocity of the car? Strategy: List your given information v i = 7.5 m/s v f = 22.5 m/s Δt = 8 s = ?
2.How far did the car from question #1 travel? v i = 7.5 m/s v f = 22.5 m/s Δt = 8 s Δd = ? Δd = (15 m/s)(8 s) Δd = 120 m
3.An airplane was initially traveling at 85 m/s when it steadily increased its velocity. What is its final velocity if the average velocity of the plane is 150 m/s? v i = 85 m/s = 150 m/s v f = ? (2) 300 m/s = 85 m/s + v f -85 m/s 215 m/s = v f Given :
4. A jogger jogs with an initial velocity of 2 m/s and speeds up to a velocity of 5 m/s over a period of 20 s. How far does the jogger go? v i = 2 m/s v f = 5 m/s t = 20 s d = ?
Velocity (m/s) Time (s) Solve for the acceleration How far does the object travel? d = ½bh d = ½(4 s)(5 m/s)+(4s)(30m/s) d = 130 m What is the average velocity?