Explanation:
direction of electric field is same as that of force experienced by the test charge
If the distance between two charges is halved, the electrical force between them increases by a factor 4.
In fact, the magnitude of the electric force between two charges is given by:

where
k is the Coulomb's constant
q1 and q2 are the two charges
r is the separation between the two charges
We see that the magnitude of the force F is inversely proportional to the square of the distance r. Therefore, if the radius is halved:

the magnitude of the force changes as follows:

so, the force increases by a factor 4.
The average speed of a moving body is given by:
average speed = total distance / total time
average speed = 560 / 25
22.4 meters per second
The skier is traveling at an average velocity of 22.4 meters per second.
Microwaves are transmitted by Radio Waves.
Answer:
527 Hz
Solution:
As per the question:
Beat frequency of the player, 
Frequency of the tuning fork, f = 523 Hz
Now,
The initial frequency can be calculated as:


when

when

But we know that as the length of the flute increases the frequency decreases
Hence, the initial frequency must be 527 Hz