the one that blocks light, like a .....

water and .....

Answer to Question .....

Well, gravitational force is the force of the attraction between any two bodies in the universe. Newtons law of gravitation is the law which gives the relation of mass of two bodies  and distances between their centres with the gravitational .....

Retardation is simply the negative acceleration.  When the velocity of a body is increasing, it will have a positive acceleration. We say the body is accelerating. While, a body will have a negative acceleration .....

second answer  Depending upon the nature of substance, chemicals can have different .....

earth is originated many years back. It was created as a small part of the Sun. Later it became cold by the rain and staying away from the .....

In simple sense, you can understand force as a tendency to change the position of a body from rest to motion and vice verca. You need to apply force to stop a moving body or to move a resting body. You require force to increase or decrease the speed .....