JOIN USSudha Subramanian brings you fun ways to learn Physics, from an innovative teacher
Ask any child. Physics, they all remark, is boring. Why is it that the universal laws we see around can actually be boring for kids? Probably because we make it so for kids!
Deepika Bhatia, a former Physics teacher and now a mother of two, says, “Most educators tend to introduce physics as a subject of formulas and definitions which morph into monsters. Monsters that haunt children in every session of physics class. Physics can be made fun if only we are ready to look at it in new light. We introduce our children to concepts like laws of motion and ask them to mug-up definitions and not help them understand the concept. This is our pitfall.”
Sir Issac Newton, the British Physicist, is credited with paving the path towards understanding motion of objects with respect to mass and force. Newton presented a whole new perspective to the way things move in the universe. He came up with three simple rules, which we now call as Newton's Laws of Motion.
Many of us are scared to even take a second look at these laws, because the applications of these universal laws are truly limitless. We follow many of these rules in our lives, not quite realizing that we are actually validating what Newton had said ages ago. Walking, sliding, swimming, jerking forwards when we apply brakes in vehicles, are all simple every day examples of Newton's Laws.
The laws the way we have learnt
First law : It is also popularly called the law of inertia that states that a body continues to be at rest or in uniform motion, in a straight line, unless acted upon by an external force.
Second Law : The rate of change of momentum of a moving body is directly proportional to the force acting upon it.
Third Law : For every action, there is an equal and opposite reaction. 'Let us now, break the laws down and make an attempt to understand them in simple terms', begins Deepika enthusiastically. The bicycle continues to be in the same position till we actually ride. That is exactly what the first law of motion states. That things continue to do that they are doing - either moving or stationary – unless acted upon by an unbalanced force. This means that the bicycle will continue to move in the same speed and in the same direction, till we change it or till we increase or decrease the speed or stop it.
Some daily examples – it is easy to take the examples of objects at rest, because in reality, the objects in motion tend to use friction and air.
That kind of situation is not possible in our homes. So, we consider the ball that rests on the table and continues to be there till we pick it up! Ever noticed how certain objects, when thrown, continue to travel in the same direction and in the same line in space? Come to think of it, this is probably why the earth just does not stop rotating. But, the same can't be said about the top that you want to spin. The earth would continue to spin in space and at the same speed as always, until we find a way to stop it!”
Deepika gives a wonderful example to explain the second law. “Nature has a way of being stable. But once, we start felling trees, nature accelerates or speedens towards global warming. This is happening all over us, and is one of the best examples for the application of Newton's second law,” she smiles.
“Yes. The law simply means that when two things of different weights are given the same force, they pick up speed differently. Quite naturally, it is easy to give a push to a little girl on a swing. However, it may be difficult if we have to push an adult on the swing. It simply means that the heavier the object is, the more force you need to move it.”
“Some daily examples – you can bike faster on a lighter bike than a heavy bike. In fact, we see the second law of motion so much in our lives that we don't really give it much thought. For example, we apply more force to lift a heavy box than to lift a light box or we end up slamming a lighter door than a heavier door.”
Moving on to the third law, she says, “What do we notice when we watch swimmers press their feet against the wall of the pool to propel themselves forward? This is the same technique used by a lot of water animals like squids and octopuses. By squirting water, they move forward. We have even watched the rocket launches when they blast off to space. This is nothing but an application of Newton's Third Law Of Motion which states that actions tend to have an equal and opposite reaction.”
So, there, it is not all that difficult. When we understand what we learn, it becomes fun and simple. So take the plunge into the world of physics and watch its marvel unfold.