HAPPY BIRTHDAY, NICK!

Please get your folders out.

Have your speed calculations paper on your desk.

Copy down tonight’s homework.

Look over your notes – QUIZ!!!

Today, we will…

Do a warm-up.

Take the quiz

Go over the speed calculations.

Learn about three different types of speed.

1. The fastest land snake is the deadly black mamba. On level ground, the black mamba can travel 158 meters in 0.5 minutes. What is its speed?

d=r●t158=r●0.5158÷0.5=r●0.5÷0.5316=r316 meters/min

2. The fastest mammal on land over short distances is the cheetah. The cheetah can maintain a steady top speed of 1.7 km/min. At that speed, how far could a cheetah run in 30 min?

d=r●td=1.7●30d=5151 km

3. The fastest land mammal over long distances is the pronghorn, found in North America. This antelope-like animal can travel up to 4 miles at a speed of 0.58 miles/min. How long would it take?

d=r●t4=0.58●t4÷0.58=0.58÷0.58●t6.9=t6.9 min

4. The slowest fish is the sea horse. If a sea horse can travel at a top speed of 16 meters/hour, how long would it take to swim the length of a football field, which is 91.4 meters?

d=r●t91.4=16●t91.4÷16=16÷16●t5.7=t5.7 hr

5. The fastest time to push an orange one mile with the nose is held by Ashrita Furman. It took him 0.38 hours to push the orange one mile. How fast was he pushing the orange?

d=r●t1=r●0.381÷0.38=r●0.38÷0.382.6=r2.6miles/hr

6. The fastest car speed was reached in Nevada by Andy Green of Great Britain . He reached a top speed of 12.7 miles/minute. At that speed, how long would it take him to drive 25 miles?

d=r●t25=12.7●t25÷12.7=12.7÷12.7●t2.0=t2.0 min

7. The fastest car in production is the Ultimate Aero TT SuperCar, built by Shelby SuperCars of the USA. If the car travels at its top speed, it can travel 3,400 meters in 30 seconds. What is its speed?

d=r●t3400=r●303400÷30=r●30÷30113.3=r113.3 meters/sec

8. Jamaica’s Usain Bolt holds the world record for the 100 meter dash. In the London Olympics, he completed the race with an average speed of 10.4 meters/second. How long did it take him to run the 100 meter race?

d=r●t100=10.4●t100÷10.4=10.4÷10.4●t9.6=t9.6 sec

9. Haile Gebrselassie of Ethiopia is the world’s fastest male marathon runner. In 2007, he ran the Berlin Marathon, taking 2.1 hours to run the 42 kilometer course. What was his speed?

d=r●t42=r●2.142÷2.1=r●2.1÷2.120=r20 km/hr

10. Speaking of marathons, Michelle Frost of Great Britain ran an entire marathon on stilts! At an average speed of 5 km/hour, how long did it take her to travel the 42 km course?

d=r●t42=5●t42÷5=5÷5●t8.4=t8.4 hr

11. Dawn Patterson Brice of the USA attained the fastest speed by a female water-skier in 1977. If she traveled at her top speed of 111 miles/hour for 0.25 hr, how far could she go?

d=r●td=111●0.25d=27.827.8 miles

12. The fastest lava flow ever observed was in the Democratic Republic of Congo in 1977. If the lava flowed a distance of 2,340 yards in 2 minutes, what was its speed?

d=r●t2340=r●22340÷2=r●2÷21170=r1170 yd/min

January 11Objective: Describe different kinds of speed

WARM-UP QUESTIONS

1. If it takes 0.2 hours for your family car to drive 5 miles on a city street, how fast are you going?2. In reality, does your car travel at the same speed the whole time? Why or why not?3.Does your car ever travel at the same speed for a period of time? Explain.

LOCATION Distance (miles)

Time (hours)

Rate(miles/hr)

A

B

C 5 0.2 25

A B C

LOCATION Distance (miles)

Time (hours)

Rate(miles/hr)

A

B 3.2 0.16 20

C 5 0.2 25

A B C

LOCATION Distance (miles)

Time (hours)

Rate(miles/hr)

A 1.5 0.05 30

B 3.2 0.16 20

C 5 0.2 25

A B C

It is very rare for things to travel at the same speed for an entire “journey,” so the average speed is just that – an average of the speeds along the journey. But, when you calculate average speed, you won’t take an average – you’ll just do this:

AVERAGE SPEED = total distance traveled how much time it took

CONSTANT SPEED is when an object’s speed does not change.

INSTANTANEOUS SPEED is how fast something is going at that instant or moment in time

BEFORE YOU LEAVE…

Describe something that moves at a constant speed.

What kind of speed does a car speedometer indicate?

What do we mean by average speed?