One example is that when their food catches fire in a cooking pot or pan, it is advisable to smother the fire by covering the fire with a blanket rather than douse the fire with water. DOeing the later will only aggravate the fire. Knowledge of basic science dictates that oil and water are immiscible liquids the oil will continue to burn even as the water is poured into the oil. More so, as the water violently evaporates due to the heat, it spreads the burning oil and hence spreads the fire.
Electromagnetic waves need no matter to travel - they can travel through empty space (a vacuum). In a vacuum, all electromagnetic waves travel at approximately 3 x 108 m/s - which is the fastest speed possible. ...
Light traveling value through an optical Fibre is, 2 x 108 m/s. Hope that helps.
Answer:

Explanation:
Given:
Mass of the cannonball (M) = 20 kg
Mass of the marble (m) = 0.002 kg
Distance between the cannonball and marble (d) = 0.30 m
Universal gravitational constant (G) = 
Now, we know that, the gravitational force (F) acting between two bodies of masses (m) and (M) separated by a distance (d) is given as:

Plug in the given values and solve for 'F'. This gives,

The same force is experienced by both cannonball and marble.
Therefore, the gravitational force of the marble is 
Answer:

Explanation:
As we know that if a charge q is distributed uniformly on the line then its linear charge density is given by

now the electric field due to long line charge at a distance d from it is given as


now the force on the other charge in this electric field is given as

