Name: ______

Chapter 19 Lab: How does friction affect an object’s motion? Lab

Seventh Grade Honors Science

Final Lab Due Date: Tuesday 12/22/15

A force is a push or a pull that affects motion. Gravity is a noncontact force of attraction that exists between all objects. Friction is a contact force that creates resistance between two objects that are toughing. Both of these forces affect an object falling towards Earth’s surface such as a parachute. The question here today is how much do these forces affect the object’s motion?

In today’s lab we will be comparing data for the release of an object for a height 4 meters, both on its own and with a parachute. How do you think friction will affect the timing of these releases? Will the parachute make a difference?

Lab Partners: ______

Lab Title: How does friction affect an object’s motion?

Purpose: To determine how friction can affect the motion of an object.

Hypothesis: I believe that friction will affect the washer’s motion by decreasing the washer’s speed by _____ times.

Materials:

·  graph paper

·  pencil

·  ruler

·  data table

·  calculator

Procedure:

1. Review all data.

2. Create a distance vs time graph based on the data of the releases with the parachute. There will be three separate lines to graph.

Follow these directions carefully:

a. graph trial number 1 in pencil, make each data point a triangle.

b. use a red pen to trace the points and create a line using a ruler.

c. now graph trial number 2 in pencil, make each data point a square.

d. use a blue pen to trace the points and create a line using a ruler.

e. graph trial number 3 in pencil, make each data point a circle.

f. use a black pen to trace the points and create a line using a ruler.

3. Compare the lines you have created, and answer your analysis questions as a group.

Data and Observations:

Height of Drop (meters) / Releases without Parachute
(seconds)
Trial 1 / Trial 2 / Trial 3
4 m / 1.01 s / 1.05 s / 1.03 s
Height of Drop (meters) / Releases with Parachute
(seconds)
Trial 1 / Trial 2 / Trial 3
1 m / 1.83 s / 1.90 s / 1.78 s
2 m / 2.85 s / 2.75 s / 2.92 s
3 m / 3.30 s / 3.41 s / 3.24 s
4 m / 4.76 s / 4.70 s / 4.82 s

Analysis Questions:

1. Calculate the average speed for each trial without the parachute. Show your work!!

Trial 1 / Trial 2 / Trial 3
Speed = ______m/s / Speed = ______m/s / Speed = ______m/s

2. Calculate the Average speed of the washer without the parachute using your answers to #1. Show your work!!

Speed = ______m/s

3. Calculate the average speed for each trial with the parachute. Show your work!!

Trial 1 / Trial 2 / Trial 3
Speed = ______m/s / Speed = ______m/s / Speed = ______m/s

4. Calculate the Average speed of the washer with the parachute using your answers to #3. Show your work!!

Speed = ______m/s

5. Is my hypothesis correct? Use the formula below to determine how much the parachute slowed the washer down. If the answer rounds to your hypothesis, then you were correct!

Average speed without parachute (#2)

Average speed with parachute (#4)

6. Friction slowed the washer, it was _____ times slower with the parachute. Explain why. ______

Final Lab Report Directions

Your Final Lab will consist of the following parts:

·  Typed final lab

o  Final graph

o  Analysis questions – answers must show your scientific knowledge

o  Conclusion – should flow well and explain results, related to Chapter 19

·  Original Lab Worksheet from class (this packet)