In which year man first landed in moon??

ANSWER :

 Neil Armstrong: First Man on the Moon

On 20 July, 1969,  the Lunar Module, Eagle, landed on the moon, in a place called the Sea of Tranquillity.

Commander Neil Armstrong was the first man to walk on the moon.

A Ship floats on water due to ??

Archimedes' principle :

An object immersed in a liquid experiences an upward force, called upthrust or buoyancy. This has been generally recognised for a long time. 

It was the Greek mathematician and philosopher Archimedes (287-212 BC) who first put it into a general principle. His statement, now known as Archimedes' principle, was that

"when an object is immersed in a liquid the upthrust is equal to the weight of liquid displaced by the object".

Thus, a rubber duck floats because its mass is equalled by the water it displaces before it physically goes under the surface. A solid lump of iron on the other hand will sink, because the water cannot displace the mass of the iron before the iron sinks.

Why do steel ships float?

It's obvious that a piece of steel will sink in water, yet ships made of steel float. There must be some other factor that comes into play to explain this. Applying Archimedes' principle to the problem, the upthrust of the water must be greater than the mass of the ship, so somehow a great mass of water has to be displaced.

This is done by shaping the hull of the ship in such a way that as the ship sinks into the water it displaces more and more liquid until a balance is reached between the mass of water displaced and mass of the ship. This general principle applies to any object made from a material that is more dense than the liquid it is in.

Longest bone in man is ??

ANSWER :

Femur ( thigh bone ) avg. inches 19.9

The femur is the thigh bone, the longest bone in the body. The lower end joins the tibia (shin) to form the knee joint. The upper end is rounded into a ball (or head of the femur) that fits into a socket in the pelvis to form the hip joint. 

When a person smokes, his blood pressure is likely to increase , decrease, remain the same , none?

ANSWER : 

Did you know that smoking and heart disease are related? Or that smoking increases blood pressure? Most people associate cigarette smoking with breathing problems and lung cancer. But people who smoke are more also likely to develop hypertension and heart disease.

The nicotine present in tobacco products causes:

Decreased oxygen to the heart
Increased blood pressure and heart rate
Increase in blood clotting
Damage to cells that line coronary arteries and other blood vessels

Mosquitoes can walk on water because ??

ANSWER:

mosquitoes could walk on the water because of surface tension. But man can’t walk on the water because the surface of the water can’t bear the weight of the man. So he gets drowned. 

The health department sprays kerosene on storage water and drainages. Because on the surface of the water exists mosquito eggs. So when kerosene is sprayed on the surface of the water then the surface tension of the upper layer decreases and the mosquito eggs are drowned into water. In this way the mosquitoes will be reduced to some extent.

The vitamin which is helpful in blood clotting ??

ANSWER:

Vitamin K refers to a group of fat-soluble vitamins that play a crucial role in blood clotting.

When iron rusts, its weight ?

decreases, increases or constant

ANSWER:

When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.

Sound Travels Fastest in?

ANSWER :

Sound travels faster in solids. Metals like iron will allow sound to travel up to eight times faster than usual. This is because solids have molecules that are tightly packed together.

Solid, followed by liquid and then gas. Sound cannot travel in vacuum since sound is a mechanical vibration and needs a medium for propagation. The higher the density of the medium, the faster the sound travels.