Lab – Determining An Average Speed

CARDINAL NEWMAN CATHOLIC SECONDARY SCHOOL

Name: ______Date: ______SNC 2D 1

LAB – DETERMINING AN AVERAGE SPEED INQUIRY: ___ / 25

PURPOSE: The purpose of this lab is to determine the average speed of an object in uniform motion (using a ticker tape and cart)

DESIGN:

In this experiment you will attach a cart to the ticker tape and let it run down a smooth, slightly inclined ramp at a constant speed.

You will gather quantitative data and use a distance-time graph to calculate the average speed of the cart

MATERIALS:

Ticker tape timer Roll of tape Cart 1 or 2 tables Small wood blocks or books (Adhesive) tape Stand and clamps for the timer and/or tape roll

PROCEDURE:

1. Place the cart at one end of the board and adjust the height of the board until the car just starts to move

2. Set up the ticker tape timer at the upper end of the ramp and either hold or clamp it in place.

3. Attach the end of the tape to the cart with a piece of adhesive tape

4. Do a trial run to make sure that the tape runs smoothly through the timer when the cart is released, and that the cart’s speed is about constant

5. Return the cart to the top of the track, turn on the timer and then immediately release the cart CARDINAL NEWMAN CATHOLIC SECONDARY SCHOOL

Name: ______Date: ______SNC 2D 2

6. Turn off the timer and stop the cart when it reaches the end of the ramp

7. Cut the tape near the timer and remove the tape from the cart

8. Record the timer setting in milliseconds

(a) Starting at the dot where the dots begin to be equal distances apart, measure the total distance traveled by calculating the length of each interval.

 EVERY 6 DOTS = 1 ms (1 millisecond)

(b) Enter the values of the time and distance measurements into the table in the OBSERVATIONS section

/10 OBSERVATIONS/TABLES (See “Sample Data” at end for example)

DOT TOTAL TIME (ms) d (CHANGE IN d (TOTAL INTERVAL DISTANCE in cm) DISTANCE in cm) 1 – 6

6 – 12

13 – 18

19 – 24

25 – 30

31 – 36

37 – 42

43 – 48

49 – 54

55 – 60 CARDINAL NEWMAN CATHOLIC SECONDARY SCHOOL

Name: ______Date: ______SNC 2D 3

/ 5 GRAPH

DISCUSSION

/ 3 1. List the following variables:

(a) Controlled variables:

(b) Independent variable:

(c) Dependent variable:

/ 2 2. The design for this experiment tried to compensate for the effect of friction. How was this done? CARDINAL NEWMAN CATHOLIC SECONDARY SCHOOL

Name: ______Date: ______SNC 2D 4

3. Using your graph, answer the following questions re: average speed.

/ 3 (a) Calculate the average speed

/ 2 (b) Did your car travel at a constant speed? How do you know.

SAMPLE DATA

DOT TOTAL TIME (ms) d (CHANGE IN d (TOTAL INTERVAL DISTANCE in cm) DISTANCE in cm) 1 – 6 1 0.5 0.5

6 – 12 2 0.9 0.9 + 0.5 = 1.4

13 – 18 3 1.2 1.2 + 1.4 = 2.6

19 – 24 4 1.6 1.6 + 2.6 = 4.2