the distance from a car from measuring position located on the edge of straight road.

Question

a. What was the average velocity of the car from t=0 and t=20sec?

b. What was the average velocity from t=10 and t=30 sec?

c. About how fast was the car travelling at t=15sec?

Answer 1

a) 300 ft in 20 seconds=300/20=15 ft/s

b) (100-200)/(30-10)=-100/20=-5 ft/s (5 ft/s in the opposite direction)

c) between 15 and 20 seconds the curve is almost flat so the gradient is almost zero, which means the velocity is close to zero (the car is starting to turn).