1. SPEED, VELOCITY, AND ACCELERATION

2. 1.A traveler covers a distance of 460 miles in a time of 8 hours. What is the average speed for this trip? speed = distance ÷ time 460 miles/8 hours = 57.5 miles/hour

3. 2.How far will a helicopter fly in 40 minutes at an average speed of 2.25 km/min? distance = speed x time 2.25 km/min x 40 min = 90 km

4. 3.Grass clippings are found to have an average length of 4.8 cm when a lawn is mowed 12 days after the previous mowing. What was the average speed of growth of this grass? speed = distance ÷ time 4.8 cm/12 days =.4 cm/day

5. 4.How long does it take a fly to fly 30 meters if it can fly at an average speed of 1.5 m/sec? time = distance / speed 30 m/1.5 m/s = 20 s

6. 5.A driver drives for 3.5 hours at an average speed of 58 miles/hour. What distance does she travel in this time? distance = speed x time 58 miles/hr x 3.5 hrs = 203 miles

7. 6.A person in a hurry averages 62 miles/hour on a trip covering 300 miles. What time was required to travel that distance? time = distance / speed 300 miles/62 miles/hour = 4.8 hours

8. 7.The speedometer of a car moving northward reads 60 km/hr. It passes another car that travels southward at 60 km/hr. Do both cars have the same speed? Do they have the same velocity? Why or why not? Same speed → 60 km/hr Different velocity → opposite directions

9. 8.Suppose a car moving in a straight line steadily increases its speed each second, first from 35 to 40 km/hr, then from 40 to 45 km/hr, then from 45 to 50 km/hr. What is its acceleration? 5 km/hr/sec

10. 9.A car advertisement states that a certain car can accelerate from rest to 90 km/hr in 9 seconds. What is the cars average acceleration? acceleration = Δ velocity / Δ time 90 km/hr / 9 s = 10 km/hr/s

11. 10.Bob is jogging at a rate of 5 meters per second. He gradually slows down so that after 5 seconds, he has stopped. What is his average acceleration? acceleration = Δ velocity / Δ time -5 m/s / 5 s = -1 m/s/s or -1 m/s 2