# How Wheels Speed and Velocity Lab Learning Objectives:

• Write a hypothesis
• Create a distance vs time graph using collected data
• Evaluate the relationship between mass and speed (F = m x a)
• Learn to read a motion graph
• Calculate speed (the slope) using the point slope formula (m = y2 – y1/x2 – x1)

Materials:

• 1 Hot Wheel or Mini Racecar (1 per group)
• 1 Meterstick (1 per group)
• 3-4 Textbooks* (Per Group)

*Something to create a ramp

• 4 Washers Stacked and Taped Together (1 per group)
• Tape (Any Kind)

Background:

Students evaluate the relationship between speed and mass by racing weighted and unweighted hot wheels down an elevated meterstick. Each group of students will develop a hypothesis statement supporting whether adding weight to a hot wheel will increase or decrease its speed. Students will then measure the time it takes a hot wheel to travel down an elevated meterstick at different lengths. This experiment is then repeated with 5 washers stacked and wrapped to the hot wheel to increase the mass. Finally, students are to graph the data as a distance vs time graph showing the differences in the hot wheel with and without the extra added mass.

Directions:

1.) Assign or have students arrange themselves in groups of up to four

2.) Have students write a hypothesis supporting whether adding weight to a hot wheel car will increase or decrease its speed

3.) Hand out pre- taped washers, Hot wheel cars, textbooks and metersticks

* Textbooks or any elevated surface works to create a ramp

4.) Measure the time needed to travel 10, 20, 30, 40 and 50 cm; when weighted and unweighted

5.) Plot the data on the graph as distance = y axis; time = x

6.) Complete the conclusion questions and post- lab questions regarding motion graphs

* The speed on a motion graph is the slope. Have students use the formula

m = y2 – y1/x2 – x1