Name: ______SN: ______

For each problem: . List the givens Speed Problems . List the formula you will use . Write the givens in your formula, including units . Show all math calculations 1. What is the average speed of a sprinter who runs the 100 m dash in 9.8 seconds? . List appropriate units on your final answer

2. At an average speed of 15 km/hr, what distance will a bicyclist travel in 4.5 hours?

3. A girl leaves school at 3:00 and walks home. Her house is 2 km from school. She gets home at 3:30. What was her average speed?

4. What distance will an automobile travel in 15 minutes if its average speed is 90 km/hr?

5. An amusement park carousel travels at an average speed of 5 m/s. If the circular track of the carousel is 60 m around, how much time will it take the carousel to make one complete revolution?

6. The Twin Cities are approximately 100 miles away. At what average speed are you traveling if it takes you 3 hours and 45 minutes to get there?

7. You travel an average speed of 58 mph on your trip to Florida. If your destination is 1800 miles away, how much time will it take to get there?

8. A rocket takes off from earth. After 3 seconds, it is 17 miles above earth. What is the average speed of the rocket during this time? Measuring Constant Speed

Problem: What is the shape of a distance-time graph of constant speed?

Procedure: 1. The illustration on this page represents a series of flash shots taken of a dry-ice puck sliding across the floor. The time between each flash is 0.1 seconds. Study the illustration carefully. 2. Position the 0-cm mark of the metric ruler on the front edge of the first puck (this is indicated by a dotted line). This position will represent 0.0 cm at time 0.0 seconds. Record this data in the data table. 3. Without moving the ruler, determine the distance of each puck from the first one. You should use the front edge of the puck each time (dotted lines have been added to help you measure). 4. Record each distance to the nearest 0.1 cm in the data table. 5. Make a distance-time graph using the data in the table. Plot the distance on the vertical (Y) axis and the time on the horizontal (X) axis. Use your ruler to connect your data points with a best-fit line. 6. Remember to give your graph a descriptive title and label both axes, with units.

Observations:

Time (sec) Distance (cm)

0.0

0.1

0.2

0.3

0.4

0.5

0.6

Conclusions: 1. What is the shape of the graph?

2. Is the speed constant? Explain your answer.

3. Calculate the average speed of the puck over the entire 0.6 seconds.