Weight and Mass- The gravitational pull of the Earth on a body is called its weight. Weight of a body can be measured by a device called Spring Balance. It is measured in Newton’s. Quantity of matter contained in body is called its Mass. It is measured by a physical balance and its units are Kilograms.
Machines
A machine is a device which helps us to apply force easily and make our work easier and convenient. A wide variety of machines are extensively used at home, in school, factories and in other activities in life. Some of the common used simple machines are: Tongs, Knife, Screw driver, Nut cracker, Tweezer, Pliers, Scissors and pulleys. There are some complex machines too such as: Bicycle, Sewing machine and Tractors.
Machines Enable us to Apply Force at a Convenient Point
While using a pair of scissors, we use force at the end of the blades whereas the cloth is cut in between the sharp edges of the blades. When we are pushing a screw inside a block of wood, we are using a screw driver, the force is therefore being applied to the handle of the screw driver, but it acts on the head of the screw and moves its sharp tip inside.
Machines Enable us to Change the Direction of Force
While drawing water out from a well, he rope is passed over a pulley. The rope is pulled downwards whereas the bucket of water is pulled upwards. Pushing the rope downward is more convenient as compared to moving it up. So the use of machines enables us to change the direction of force.
Lever: Lever is a rod which moves freely about a pivot. A crowbar is a perfect example.
Fulcrum: It is a pivot abut which a rod or a system mover freely.
Load: The weight of an object required to be lifted is called the Load.
Effort: The force applied on an object is called effort.
There are three types of levers depending upon the relative positions:
First Type: The first type of lever involves the fulcrum in between the effort and the load.
Second Type: In this second type of lever the load is in between the fulcrum and the effort. Wheelbarrow is a lever in which the load is in between the fulcrum and the effort.
Third Type: In this third type of lever, the effort lies in between the fulcrum and the load. Tongs and fishing rods are examples of this category.
Law of Moments: Clockwise = Anti- Clockwise
Formula: Force X Distance
Pulley
A pulley consists of a wheel that turns freely about an axle passing through its centre. It is designed in such a manner that its periphery (Outer part) has a groove over which passes a rope or a chain. Pulling or releasing the rope turns the wheel. The pulley enables us to change the direction of force.
Equipment
- Meter’s Rule.
- Newton Meter’s.
- Block of wood used for balancing.
- Pen to record the results.
Method
- Firstly, I had gathered all the equipment and had set up the experiment. As I was accomplishing the experiment alone, it took me a while to conduct the experiment.
- Secondly, I had started to conduct the experiment by placing the weights on both the sides so they can balance. As I had conducted the experiment before I achieved the desired results.
- Thirdly and lastly after accomplishing the experiment I had put all the equipment back to their original places and copied down the results in a table format which are mentioned in the results column.
Prediction
I predict that as the distance decreases, the force required increases. I also predict that as the object moves away from the pivot, the effort required in less.
Fair Test
There was only one issue for the fair testing which is, mentioned below-
- I had used the same Newton meter same time as it might not have the same spring inside which would have lead me inaccurate results.
Safety
While I was conducting the experiment there weren’t much safety issued to be observed but some of the safety issues are mentioned below-
- I was careful, while handling with the weights as if they would have fallen on someone’s foot it could have been injurious.
- While carrying out the experiment, there were many people doing important work, I was careful not to cause noise pollution.
- Lastly, I was careful while handling with the ruler as it was delicate piece of equipment.
Results
Conclusion
My results agree with my prediction and all the columns in the results table are balanced. In other words:
ANTI- CLOCKWISE = CLOCKWISE
Evaluation
I believe that I have been successful in accomplishing the experiment as I achieved the results which I had desired. I also believe that I have achieved my goals which were to obtain perfect results. Even though I was successful in obtaining perfect results, I had encountered some problems which are mentioned below-
- The first problem I had encountered was, while I was trying to balance the weights on the meter rule, I had kept on changing the positions of the weights from left to right as it would not balance both the ends even though my calculations were correct.
- Secondly, I think there was some problem on the meter rule as the as the weights would not balance perfectly.
- Lastly, I think there was some with the block of wood which was used to balance the meter rule. I think the plank of wood was defected i.e. chipped off.
Some Simple Machines
