What is mean by combination reaction ?

Those reaction in which two or more substances combine to form a one new substance are called Combination reaction

In this reaction, We can add :

In this, Hydrogen is an element and Oxygen is another element. Both are combined to form compound 'Hydrogen oxide'. Hydrogen oxide is commonly known as water.

sonar - device which is used to find the submit submarines, sankalp ship. sonar waves consists of a transmitter and detector which are installed in the observation centre on board of a ship. the ultrasonic waves are sent into the sea at high frequency about 1000 khz in all direction.

answer; how far out of place which the object finished relative to the starting location;