Ask To Science !

1: Why does a baby's rattle only make noise when the baby moves it back and forth? 

When the rattle accelerates the beads inside it continues on and hit the walls of the rattle. The rattle then makes noise.

2: What makes bath-room mirrors fog up?

After a shower, the air in the bath-room is warm and steamy. When it hits a cold surface such as a mirror, the air cools down and changes back into tiny water droplets. These water droplets then fog up the mirror.

3: Why is the beach-umbrella attached to a long pole that sticks into the sand?

To prevent the umbrella from rotating about its tip when the wind blows, the sand must exert its force far from the tip.

4: What happens when you touch a sensitive plant?

If one of the leaflets is touched, it folds inward on to a vein, and the movement is transmitted from one leaflet to the next until the whole leaf has folded.

5: How a certain insect such as the Pond-skater stand on water?

It is due to surface tension, water molecules at the surface are under tension, being pulled inwards by their neighbours. This results in a thin skin that can support the weight of the Pond-skater.

6: Why honey is extracted with a centrifuge?

Honey is highly viscous and on the surface of eachbpore it exerts strong viscous forces to pass through the pore. Gravity alone is often not enough to keep the honey moving and so centrifuge is used.

7: How does a fan increase the total energy of the air that passes through it?

In an open room fan, the air's pressure must remain roughly atmospheric. Instead, the air's speed increases. The room fan draws air from a wide region behind the fan and sweeps it into a narrow fast moving beam in front of the fan.

8: Why the vinyl upholstery tends to crack in very cold weather?

Cold shifts it to the glassy regime and it becomes brittle.

9: Why do you feel cold after a shower?

Your body is always giving heat. When you are wet, your body heat turns some of the water on your skin into the gas water vapour. This change from liquid to a gas is called evaporation. As this evaporation uses up heat, you begin to feel shivery after a shower.

10: Why is it so much easier to shave wet hair than dry hair?

Water plasticizes hair temporarily softening it.

11: Why does a sprouting plant grow upwards?

Because its leaves must reach the Sun. A plant starts life as a bulb or seed in the soil. The shoot bearing the leaves, pushes upwards towards the sunlight to start making food for the growing plant.

12: Why is it easier to unscrew a nut with a spanner than with your fingers?

Because the spanner's length or long handle increases the turning effect or moment of the force.

13: Why a round-bottomed bottle fall over while a flat-bottomed bottle tend to remain upright?

A round-bottomed bottle's centre of gravity descends as it tips, while the flat-bottomed bottle's centre of gravity rises as it tips.

14: Why do zips have teeth?

Without their teeth, zips could not open or close. The two rows of teeth are joined by a slider, which locks them together or pulls them apart.

15: How do hang-gliders hitch lifts?

When the Sun heats the land, the land then warms the air above it. Warm air is lighter than cold air, and it rises up into the sky. Hang-gliders use this rising warm air to help them to fly. The rising currents of warm air are called thermals.

16: How does a knife cut?

The knife is simple a wedge that mechanical advantage to convert small forward forces into large separating force. When you push down the knife, its cutting edge permeates while the tow inclined surfaces of the blade exert huge horizontal forces to halves.

17: How does a trumpeter play trumpet?

Brass instruments such as the trumpet have an open mouth. The trumpeter sets the air in the mouthpiece vibrating by blowing raspberries into its.

18: Is it a good place to stand in a thunder-storm under a tall tree?

No. Tree attracts lightning.

19: Why the beehives are six-sided cell?

The cells of worker bees are all made alike. This standardized, modular design saves time and space in a beehive. A bee is an exceptional architect working without ruler or compass in the darkness of the hive.

20: Why a covered pot of water heats up and begins to boil more quickly?

The cover prevents evaporation from taking heat from the pot.

21: How do you adjust the camera's aperture and shutter speed to make the background of a picture appear blurr?

One should use a large aperture and a short exposure time.

22: You observe the lid bowed inward of a sealed container with half full of hot food put inside the refrigerator. Explain.

Cooling the air inside the container reduces its pressure. The resulting pressure imbalance across lid pushes the lid inward.

23: Where are the real images located in the binoculars?

Binoculars are a pair of Keplaraian telescopes with prisms added to form upright real images. The real images are located a short distance in front of the eye-piece.

24: How does a missile fly between the Y-shaped arms of a catapult?

The missile is launched by converting the potential energy stored in a stretched piece of elastic into kinetic energy

25: How is the Earth rotating?

The Earth moves in three ways: on its own axis, through space as it orbits the Sun and as part of the Solar System moves through space as the Milky Way galaxy which rotates.

26: Why the wall of a smaller soap-bubble always bulges into the space of a larger soap- bubble?

The pressure inside a smaller bubble is greater than the pressure inside a larger bubble.

27: A roller-coaster in a theme park has no motor. Then how is the ride possible?

On a roller-coaster the carriages are first raised to a great height and then released. The force of gravity gives them enough power complete the ride even when they loop the loop.

28: Styrofoam coffee cups are made from a frothy mixture of polysterene and gas. In which regime it is at both temperatures?

Polysterene is in the glassy regime at both temperatures of room and coffee.

29: What happens when tennis player serves?

Muscles are working not only in the arms, but in the neck, back and legs, to keep the body well-balanced and supple, in order to run forwards without causing injury.

30: When do tornadoes occur?

Tornadoes occur when a funnel of violently spinning air forms beneath a thundercloud and swoops to the ground. At the centre is an area of low pressure that sucks everything in its path like a giant vacuum cleaner.

31: Why is it so difficult to get ketchup to flow out of a brand new glass bottle?

Viscous ketchup requires a larger pressure difference to flow rapidly. Gravity alone can not provide enough pressure difference.

32: What happens when things burn? 

Things burn when they get hot enough to react with oxygen in the air around them. Fire needs three things namely heat, fuel and oxygen. Fire goes out if any one of them is taken away.

33: How do orbiting things keep to their path?

An orbit is a circular or oval path around a centre of some kind. All orbiting things keep to their path because a forg comes from the centre and pulls them into an orbit. Without these central forces, all the satellites, moons, planets and stars would leave their orbits and fly off into space.

34: Why does metal feel cold?

When you touch a metal it feels cold. The heat from your hand flows out into it as metal is a good conductor. It is not metal that is cold, but it is your hand losing heal.

35: How does a toy flying top ascend?

The spinning rotor wings force air downwards, so that the air above them gets thinner and the air below thicker. The greater pressure from below makes the toy ascend.

36: Why there is a flight ceiling for airplanes?

When the air becomes too thin, the wings can not obtain enough of a pressure imbalance and lift to support the plane's weight.

37: How a Pole-vaulter gets into the air?

Strong internal forces between the particles inside a Pole-vaulter's pole give it elasticity and stop it from breakup. Instead, the pole bends, then springs back to thrust the vaulter in to the air.

38: Why is it exhausting to run on soft sand?

You do work on the sand as you step on it, but the sand does not return this energy to you as you lift your foot back up again.

39: Why is it so important that a microwave oven turns off when you open the door?

Releasing the microwaves into the room would not be healthy.

40: How does your bread toaster work?

Red-hot wires heated by electricity toast bread in a toaster. The hot wire gives out heat rays that heat everything they meet. This kind of heat flow is called radiation.

41: What is blood pressure?

Blood pressure is the pushing force given to blood by the heart the first reading gives blood pressure during heart beats: the second, pressure between heart beats.