Laboratory activity doing work with machines

1. Assessment Objectives:
• Identify some simple machines.
• Demonstrate how machines make work easier.
Criterion C: Processing and Evaluating
Maximum: 8
At the end of Grade 7 and 8, students should be able to:
i. present collected and transformed data
ii. interpret data and describe results using scientific reasoning
iii. discuss the validity of a hypothesis based on the outcome of the scientific
investigation
iv. discuss the validity of the method
v. describe improvements or extensions to the method.
Student Name: CN 1st
Term SY 2018 - 2019
Level: Grade 8 Date: Parent’s Signature
Subject: Science Teacher: Armand Anthony L. Galicia
Formative Assessment – Laboratory Activity Unit/Topic: Doing Work with Machines
Achievement
level
Level descriptor
0 The student does not reach a standard indicated by any of the descriptors below.
1–2
The student is able to:
i. collect and present data in numerical and/or visual forms
ii. accurately interpret data
iii. state the validity of a hypothesis with limited reference to a scientific investigation
iv. state the validity of the method with limited reference to a scientific investigation
v. state limited improvements or extensions to the method.
3–4
The student is able to:
i. correctly collect and present data in numerical and/or visual forms
ii. accurately interpret data and describe results
iii. state the validity of a hypothesis based on the outcome of a scientific investigation
iv. state the validity of the method based on the outcome of a scientific investigation
v. state improvements or extensions to the method that would benefit the scientific
investigation.
5–6
The student is able to:
i. correctly collect, organize and present data in numerical and/or visual forms
ii. accurately interpret data and describe results using scientific reasoning
iii. outline the validity of a hypothesis based on the outcome of a scientific investigation
iv. outline the validity of the method based on the outcome of a scientific investigation
outline improvements or extensions to the method that would benefit the scientific
investigation.
7–8
The student is able to:
i. correctly collect, organize, transform and present data in numerical and/ or visual
forms
ii. accurately interpret data and describe results using correct scientific reasoning
iii. discuss the validity of a hypothesis based on the outcome of a scientific investigation
iv. discuss the validity of the method based on the outcome of a scientific investigation
v. describe improvements or extensions to the method that would benefit the scientific
investigation.

2. ATL Skills:
 Information Literacy Skills – Collect, record, and verify data; Process data and reports results
 Creative Thinking Skills – Design improvements to existing machines, media, and technologies
Materials:
Part A Part B Part C
Pencil or Round Stick Dynamic Cart Pulley
Ruler Wooden Board/Inclined Plane Thread
3 coins of the same kind Rubber Band 2 small weights
Object to support the inclined plane
Procedure:
As you perform the procedure, write down your observations right away under OBSERVATIONS.
A. Experimental Set-up A - LEVER
1. Refer to diagram A above. Place a pencil under the midpoint of a foot-ruler and locate the point
where the ruler balances. Place a coin on each end of the ruler and balance.
2. Next, place a coin on top of one coin. Observe and record what happens to the setup.
3. Remove the coins and again set the midpoint of the ruler over the pencil. This time, pile all coins
on one end (Diagram B). Press down the other end and observe what happens.
4. Then change the position of the pencil under the ruler, as in Diagram C. Press down the other end
and observe what happens.
5. Repeat step 4 at another position of the pencil (see Diagram D).
Guide Questions
1. In step 2, what happens when a third coin is added on top of one coin?
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2. What would you do to make one coin balance
a. Two coins?
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b. Three coins?
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3. With all coins on one end (step 3 to 5), describe how the push changes as you change the position of the
pencil.
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3. B. Experimental Set-up B – Inclined Plane
1. Hang the car with a rubber band. Life the card 15 cm high. Observe how far the rubber band is
stretched.
2. Then pull the car with rubber band along an inclined board 15 cm high. Observe how the rubber
band is stretched.
Guide Questions
1. When is a greater force exerted to raise the cart 15 cm high – when you lift it vertically or when you pull it
up an inclined plane?
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2. In which case does the cart travel a farther distance, when lifted vertically or when pulled up an inclined
plane?
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3. Write a sentence, describing how FORCE exerted and DISTANCE traveled are related.
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C. Experimental Set-up C – Pulley
1. Prepare the set-up as shown in the figure above. Raise the pulley system to enable the
boxes to move freely when pulled or pushed.
2. Pull one box downward.
3. Then lift one box.
Guide Questions
1. In procedure experimental set-up C, what happens to one box as the other one is pulled down?
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2. What happens when one box is lifted?
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3. What is changed in both cases?
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