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What is the Role of Physics in our daily life?
On our home planet, “Earth”, several events happen every day. We experience some incidents daily, while others happen less frequently, sparking our curiosity. Physics can answer anything that you are curious about, from the rainfall to everything that you can see and do. Let us dive deep to understand what part physics plays in our everyday tasks and how it assists us in doing our duties effectively.
Walking
Walking involves a complex interplay of several principles of physics. It consists of laws of inertia, gravitational law, friction, kinetic energy, potential energy, etc. Let us take some examples to understand how physics is applied in the act of walking.
When we put our foot on the ground, we exert a download force on the ground equal to our weight, which is represented by the equation w=mg, where m is the mass and g is the acceleration due to gravity. Newton's third of motion states that for every action, there is an equal and opposite reaction, so when our foot contacts the ground, the ground exerts an equal and opposite force on our foot.
Kinetic and potential energy come into play when we move our legs forward or backward for walking. When we move our legs, kinetic energy reaches its maximum and potential energy at zero. But when our leg reaches the belly or arc, potential energy reaches its maximum. And when we put our next step, this potential energy is converted into kinetic energy. Similarly, friction between foot and ground provides us with the required traction, which protects us from falling.
Seeing
You might not know that human vision relies on the principles of physics, which include optics, neural processing, and more. Our eyes are like a camera that captures everything and sends it to the brain. Similar to a camera lens, it has a convex lens that helps focus light on the retina. The coloured part of the eye, the “iris” acts as an aperture and adjusts the size of the pupil according to different lighting conditions. Iris-created image is real and inverted, just like a camera. The photoreceptors convert the light into electrical signals. These signals are sent to the brain by the optic nerve. These electrical signals are analysed and arranged into a form which our eyes can see.
Also, the properties of light help us understand how our eyes perceive shapes and colours. For example, light consists of seven colours, and when it falls on an orange colour balloon, it absorbs all the colours except the orange colour. So, that’s how we interpret the colour of the balloon as orange. Similarly, when light falls on a white object, it absorbs all the colour except white.
Cooking
Cooking involves temperature, heat transfer and work done, which is a part of thermodynamics. According to thermodynamics principles, heat transfer takes place from hot to cool surfaces. That’s why when we put a pan with water on a burning pan, it started transferring its heat to the pan. Thermal expansion is another concept in thermodynamics in which certain material expands in response to temperature changes. You might have noticed this while pouring hot water into a plastic bottle, causing it to deform due to heat. Manufacturers take into account thermal expansion while designing cooking utensils.
Slicing fruits and vegetables
While cutting fruits and vegetables, we don’t realize the role that physics plays in it. To chop a fruit or vegetable, we have to exert pressure on it. And we all know by increasing pressure, we can easily cut them. Pressure is directly proportional to force and inversely proportional to area (Pressure = force/area). So, when we exert more pressure on an object, we can easily cut it. But if we cut the same object with a knife with thicker edges and apply the same force, we can’t cut it. We learn from our experiences that knives with small surface areas cut more efficiently.
Opening/closing doors
Physics is also applied to the task you do every day- opening and closing doors. The concept behind the opening and closing of the door is the torque, which is the force required to twirl/twist an object around an axis. So, when a handle is far from the hinges, it is easy to open or close the door as it creates torque with less effort. But if the handle is closer to the hinges, you need to push harder to create enough torque to open the door. Also note that when we open the door clockwise, the torque is positive, and when we open it anti-clockwise, the torque is negative.
Final words
We have here tried to cover some of the applications of physics in our day-to-day lives. But physics is in every part of our reality and helps us understand the world in countless ways, from technology and engineering to medicine and biology and everything in between. So, study physics, considering how it helps uncover the mysteries surrounding us and appreciate its role in our lives.
