t (seconds) 0 4 8 12 16 Velocity (ft/sec) 0 11 22 43 69 A. Estimate how far the car traveled during the first 16 seconds using the left-hand sums with 4 subdivisions. Answer: B. Now estimate how far the car traveled during the first 16 seconds using the right-hand sums with four subdivisions. Answer. Determine which of the two is underestimate: (choose A or B) feet feet

(7) Two cars (Car A and Car B) travel on parallel east-west roads (Road 1 and Road 2) located 10km apart. Car A is travelling west on Road 1 at a speed of 80km/h. Car B is travelling east on Road 2 at a speed of 50km/h. How fast is the distance between them changing, when the distance between them is 15km? Hint. Draw a picture to get started.

A toy aircraft is flying East passing above a radar at a constant height of 30 feet from the ground and it casts a shadow on the ground that is moving at the rate of 10 feet per second. At what rate is the distance from the radar to the aircraft changing at the instance where toy aircraft is 50 feet away from the radar?

B. A photographer is stationed 250 feet from the base of a tall tree. She observes a koala bear climbing up the tree at a rate of 1.5 feet per second. At the instant when the koala bear is 5 feet up the tree, how fast is the distance between the photographer and the koala bear changing?