Grade 5 Science

Simple Machines:


Websites used to plan these classes:

http://www.grc.nasa.gov/WWW/k-12/Summer_Training/KaeAvenueES/SIMPLE_MACHINES.html


http://sciencenetlinks.com/lessons/move-it-with-simple-machines/

Thank you to both sites for wonderful ideas.

Lesson 1:


Materials needed: A large box filled with heavy books. You should not be able to lift it.

Final assignment:


How could I lift this box to the top of the cupboard for storage (without using any engine or electricity)

Students try to push the box on the floor to find out how heavy it is. They should not try to pick it up for safety reasons.

It is expected that students have some ideas as to how to lift the box. These should be written down.

Lesson 2:


Working with the simple machines:

Pulley: As given in the NASA site. I like the question: What is the easiest way to lift the jug?

Wedge: As given in the NASA site.


Inclined Plane: As given in the NASA site.


Wheels:

Materials: Block of wood. Spring scale. Childs truck.

Question: Why would I use the truck to pull the wood, rather than just pulling the wood on the floor?

Screw: NASA site


Lever:

Materials: Long board to act as the lever. Paint bottle to act as the fulcrum. Pile of books.
Set the lever up with the fulcrum in the middle.

Question: How could you lift 6 books with just one book?

For each station, have the students draw what they did, including arrows that show the direction they applied the force and the direction of the movement of the object they applied the force to. If applicable, they should also note down the force used.

Assessment:

Anecdotal evidence:
Are students interacting reasonably with the equipment attempting to answer the question.
Are they trying new and interesting ideas of their own?
Are they on task and engaged if on task is defined as working with the equipment to see how the simple machine operates even if not directly answering the question
In asking them about their activity, are they able to explain what they have noticed. Are they exploring further?

Look at the work they handed in. Did they notice correctly the difference in movement? Did they notice the difference in force required?


Lesson 3:


Discuss results of each station. Go over them, discuss what they learned from each. Talk about how they are used and how they make life easier for us. Ask students to think about how you pay for the lower force used with each machine. Also have them notice how when working with one of these machines, the direction of the force applied is usually different to the direction of motion achieved.

Students enjoy youtube videos here for each machine just to help them understand

Lesson 4:


The Archimedes Screw:

Make simple Archimedes screw and demonstrate its use to students.

youtube videos are helpful here

Lesson 5:


Allow each student to pick one of the machines. Ask them to develop a question they could perform a simple controlled experiment to answer. Check they have correctly controlled the variables. Allow them to perform the experiment and answer the question. This can then either be written up, or demonstrated to the class.

Some of the questions posed and answered by my class:

Screw: Will an archimedes screw work better with the tubing rolled close together or further away?
Will an archimedes screw work better with thick tubing or thin tubing?

Lever: Can I balance a lever? Answer: No. Too difficult in practice

Wheel and axle: Is it better to pull a truck on a string at an angle, or directly in the line of motion?

Pulley: Is it better to pull something up with a pulley by pulling outwards (at 90 degrees to the pulley) or straight down. Answer: It made no difference to the force but you could pull something up further by going out sideways because you could go further.

Inclined plane: Does the angle of the plane make a difference?
Does a car travel further if released at the top if the plane is at a steeper angle?

Lesson 6:

Everyday use of simple machines: Bring in examples of simple machines in everyday life:
corkscrew, bottle opener, spade, wheel barrow (or a kid size one) broom, butter knife,

Students have to identify these objects.

Lesson 7:

Back to the original problem: How are you going to lift the heavy box to the top shelf. Students answer using a diagram and a simple explanation including naming the simple machine. This is the final assessment for the unit

Lesson 8:


edheads.org has a really fun activity for simple machines.