Measuring Speed and Acceleration

Average Acceleration Lab

1. Measure out 10 meters on the ground. Mark both ends. Now have

a partner time you as you walk starting at zero to 10 meters. Do this 3 times. Write

your times below in seconds. As you do the lab don’t forget appropriate units!

1. ______2. ______3. ______

Now help your partner(s) do their walk.

Add your times (total time): ______. Your distances (total distance): = 30 meters

2. Find the average speed for yourself. Use the formula for average speed below:

total distance / total time = average speed

Your average speed (m/s) =

Now find your average time (add your times and divide by three) =

Describe your velocity. Velocity is speed and direction. Write your average speed

and include the direction you were going (north, south, towards the office, etc.)

3. Were you accelerating during this exercise (speeding up, slowing down, or changing

direction?). Describe how you were accelerating. Hint: you started at 0m/s and

finished at some positive speed).

4. Find your acceleration by plugging in your initial speed (which was zero m/s),

your final speed (your average speed from above), and your average time into the

formula below. Note! This is average acceleration because we are averaging your

three speeds that you walked during three different times!

(final speed – initial speed) /average time = average acceleration

initial speed = 0m/s

final speed (your average speed from above) = ______

average time (your average time from above) = ______

Now find your average acceleration using the formula above. Show your work below and don’t forget to include the correct units (m/s2)!

5. Write your average acceleration here: ______

6. What are the three ways that objects in motion can accelerate?

7. If a planet travels around the Sun at a constant speed how can it be accelerating?

(answer this question below and then turn the paper over!)

8. Graph a person changing their speed while walking using the table below. Indicate on the graph with arrows and words where the person is positive accelerating, walking at a constant speed and negative accelerating (decelerating).

Set up the graph with time in seconds on the x axis and speed in m/s on the y axis.

9. When you accelerate or decelerate suddenly in a car you feel a push (a force!) either forwards or backwards depending on the type of acceleration. Explain why changing direction is also a type of acceleration based on the push you feel in a car if you suddenly turn the wheel while moving at a constant speed.

10. Although the Earth is accelerating because it takes a curving path around the Sun it is also accelerating because it follows an elliptical orbital path. Use the formula for acceleration below and the following information to find the acceleration of Earth between a solstice and an equinox.

Show your work! Acceleration = (Final Velocity – Initial Velocity)/ Time =

Initial Velocity at Winter Solstice = 29.29 km/s

Final Velocity at Spring Equinox = 30.29 km/s

Time = 7,889,400 seconds

Write your answer below. Don’t forget the appropriate unit!