Innovative Investigations: Block and Tackle

DATE: 22 Zilhijjah 1433/8 Nov. 2012

Block and Tackle

AIM:
To build a simple block and tackle and a pulley with hangers and investigate how they work and which is easiest.

load; plasticine

MATERIALS:
- 3 coat hangers
-  plasticine
- tape
- scissors
- pencil
- paper cups


METHOD:

cup holding load

First we used the paper cup and yarn to make a bucket to hold our load.

Then we made the Block and Tackle with two hangers, some yarn and tape; we tied one end of the yarn to one hanger and taped it in place. Then we wound the yarn around both hangers and held on the the other end of the yarn to pull. The bucket was attached to the lower hanger.

The second pulley was made by attaching the bucket to one end of the  yarn and looping the other end over the curve of the hanger.


RESULTS:

Block and tackle in action

load up

simple system pulley using a hanger

OBSERVATIONS:
1.Which pulley system worked better?
The simple pulley.

2.Why?
It could be pulled more easily.

3. Did both pulleys need the same amount of force to work?
No, the block and tackle needed more force to move (it was difficult to use too).

 4. Which needed more force?
The Block and Tackle.

5.Why did it need more force to lift the load?
The yarn had to move over more distance to work and had to the lower hanger as well.


(Design of Block and Tackle taken from :Wheels, Pulleys and Levers"  pulished by Pustak Mahal, India)

Innovative Investigations: Measuring Distances

AIM :
To find out which type of object will fall the furtherest distance and which type will fall the least distance.

MATERIALS:
1. ball
2. plastic spoon
3. metal spoon
4. paper
5. shirt
6. measuring tape
7. electric tape

METHOD:

tape marking standing place

A piece of electric tape was taped to the ground to mark the place from where the objects would be thrown. The objects were thrown one at a time. Then we measured how far it fell. We tried to exert the same force for each object. 

signalling all is ready and subject can now throw object

measuring the distance the object fell

measuring tape

RESULTS:

 

OBSERVATIONS:

1. Was force exerted the same?

Yes

2. Which object fell furtherest distance?

The ball.

3. Which object fell the least distance?

Paper.

- Paper is light so it did not fall far and often spiralled to the ground.

 CONCLUSION:

We learned that the smaller an object is the further it goes. The distance an object falls is determined by velocity/ speed, shape and size of the object (Air Resistance.)