I Should Have Known Trivia Quiz

Answer: Gravity

Gravity is the force that pulls everything towards the earth. It does not let anything fly away from earth unless you put enough effort to get away from it like launching a rocket. Next time I will be careful while throwing anything into the air.

Answer: It was due to friction between my hands

Rubbing two things creates heat. This heat is generated due to friction between them. Friction is a force that comes into play when two or objects get rubbed against each other. This friction opposes the motion of the body and in this process, it generates heat.

This method is still used by many people to create fire in places where no other source of heat is available. They rub pieces of wood against each other, which creates enough heat, so that wood can burn.

Answer: It was due to the surface tension of the water

Not a surprise to see a mosquito on the water as this is how they breed. Surface tension is a property of a liquid in which molecules on the surface bind themselves such that lightweight objects (like insects) cannot break them. Hence, they can stand on water. But heavy things (like humans) can easily break that binding force and hence will fall into water if I try to stand on it.

Answer: The buoyant force of water was pushing the balloon upward

So, I came to know that the reason for this is buoyancy. It is the phenomenon that is responsible for the floating of light things on any liquid. Whether something floats on water or not depends on its relative density. Suppose I have a hollow ball of iron and a solid ball of iron. Now this hollow ball is filled with air inside due to which its overall density will decrease. If this density is less than the water, then it will float on water.

But the solid piece of iron can't float on water because it has a density much higher than that of the water.

Hence for the hollow ball, we can say that water is pushing the ball upward with a force against gravity which we called buoyant force and the phenomenon is called buoyancy.

Answer: Pressure at the knife edge is high enough to cut through the onion

And the correct answer is pressure. The pressure is defined as the ratio of force per unit area. So if we have to increase pressure, we can either increase the force or decrease the surface area where we have to apply pressure. The knife's edge has a very small surface area, so it can apply more pressure to the onion which ultimately cuts it. Knives and other sharp objects can easily pierce through our muscles if not handled carefully. So never play with those items and always keep them stored away safely.

Answer: Due to air resistance being greater for the plain paper

If you drop a feather and a stone from the same height, the stone will fall faster than the feather. This is because of air resistance. The air resists the motion of lighter weighted objects or objects with large surface areas, making them fall more slowly. That is why people jumping from planes use parachutes as it increases their surface area and hence decreases the falling speed. If the same experiment is run under a vacuum, both stone and feather will reach the ground at the same time.

The same applies to the crushed and the plain paper situation.

Answer: Refraction of light

She was talking about the refraction of light. Whenever a light source travels from one medium to another medium, it bends from its original direction. Light from the Sun, when it hits my magnifying glass, can get focused on one point due to refraction.

When this concentrated light is kept aimed at a single spot, it will cause heating and can cause a fire if the spot is on a flammable object like a thin sheet of paper.

Answer: It is due to a change in inertia of my body

Inertia is the state of a body where it doesn't want to change its current position. When a force is applied to a body, it resists that force due to inertia. As the bus moves forward, my feet move with the bus because they are on the floor, but due to inertia, my upper body falls backward. Similarly, when the bus stops, my feet stop with the bus but my body keeps moving due to inertia and hence I fall forward. You can minimize this effect when traveling if you always hold something strongly during the starting and stopping of the vehicle.

Answer: Salty water

A conductor is a material or a solution that lets electricity pass through it. If I touch a naked wire, electricity will find a way to ground through my body, and hence I will get electrocuted. Salty water is a good conductor of electricity because it contains ions (positively and negatively charged extremely small particles). Never ever touch any wire by yourself. Let the experts handle them.

Answer: Total internal reflection of light

When sunlight hits the raindrop, it gets totally internally reflected. That means the light enters into the raindrop but instead of passing through it, it gets reflected in the same direction from where it came. When the light gets reflected it gets scattered into its component colors while coming out of a raindrop and creates a rainbow.