You sit in the chair and study for hours for the exam the next day.
Then you wrap up and run to the couch. You sit and watch television, unwind a bit.
Your mum calls you in distress from the kitchen. A heavy flour box is almost falling down on her. You throw your hands up in the air to hold it till your mum is safe. Your hands hurt as you bring them down.
Have you been working hard? Or hardly working? Of course, working hard you would say! But according to science it is the latter. You have hardly done any work.
Mind boggling, isn’t it?
The word work in English refers to anything physical or mental that you do. But in science work is said to be done only if a force applied to the object moves the object in the direction of the force. Therefore, when there is no movement like when you study, when you watch tv or when you hold a box without moving it, scientifically no work has been done. Getting tired doing something does not necessarily mean you have done work!
The work is calculated by multiplying the force applied by the amount of movement of an object makes. Have you ever tried lifting your friends? The higher you lift them, means more work done by you. When you travel in a bus, the more distance bus travels the more work it does.
We use machines in our daily lives. Simple machines to make work easier. Ancient people invented simple machines to make their lives easier. One of the simple machines we use of in our lives on the daily basis is wheel. Think of every time you have travelled in a car. Without wheel, you probably would have walked that distance. One thing is clear. Machines allow us to do the same work by applying a smaller force over a greater distance.
The see-saw you love in the park is a simple machine called the lever. Doesn’t see-saw let you lift your friend up and down so easily? Have you ever seen packers unload heavy items from the back of a large truck? They create a flat, slanted surface. This ramp like thing makes moving and lifting things easier. Such an inclined plane is also a simple machine.
Simple machines make up complex machines like vehicles. There are more simple machines that we will explore some other time. Till then, you get yourself to do some work!