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Different Speeds Review

Last updated over 5 years ago

10 questions

1

1

1

3

1

1

4

3

3

5

Watch the video to refresh your memory on average and instantaneous speeds. Then answer the questions. 

Question 1

1.

What is average speed?

Question 2

2.

What is instantaneous speed?

Question 3

3.

What does the speedometer on a car measure: average speed or instantaneous speed? How do you know?

Question 4

4.

Waldo gets stopped by the police, and the policewoman tells Waldo that she caught him on radar doing 50 miles per hour in a 40 miles per hour zone. Waldo responds thusly: “No way I was traveling 50 miles per hour. I sat at home for 1 hour and then drove for 1 hour before you stopped me. I traveled 50 miles total in that second hour. So my speed was 25 miles per hour. That’s well under the speed limit.”
Show how Waldo came up with the speed of 25 miles per hour. Then decide whether or not Waldo should get a speeding ticket and explain why.

Question 5

5.

We haven’t discussed how to calculate instantaneous speed. How do you think you might go about doing that?

Question 6

6.

You are sitting by the side of a country road, and a car comes speeding along. Suddenly it stops in front of you for just a second, then speeds off again in the same direction, going faster and faster as it disappears from view. Which of the following is true regarding the car’s motion?

Its instantaneous speed was never zero

Its average speed is the same as its instantaneous speed

Its average speed during the motion was equal to zero

Its average speed was never equal to zero

Question 7

7.

For question 6, explain how you got to your answer. Why was the answer you picked true, AND explain why the other questions were incorrect.

Question 8

8.

Show all Work: A runner makes one lap around a 200 m track in a time of 25.0 s. What was the runner's average
speed?

Question 9

9.

Show all Work: Hans stands at the rim of the Grand Canyon and yodels down to the bottom. He hears his yodel back from the canyon floor 5.20 s later. Assume that the speed of sound in air is 340.0 m/s. How deep is
the canyon?

Question 10

10.

The graph below shows Daisy walking to school from home. Highlight (in BLUE) on the graph where Daisy stopped to get breakfast (aka her speed was zero). Then calculate her average speed for her entire journary from home to school. (Show all your work)