Answer:
The new force becomes 4 times the initial force.
Explanation:
The force of attraction or repulsion is given by the relation as follows :

Where
d is the distance between the interacting charges
F is inversely proportional to the distance between charges.
If the distance is halved, d'=(d/2), new force is given by :

So, the new force becomes 4 times the initial force.
Detergents are special, powerful cleansers that can break up dirt, oils, and grease in clothing or on dishes.
Cleaning solvents are used to remove oil, grease, solder flux, and other contaminants.
Acid cleaners are generally used to remove mineral deposits and are useful for descaling dishwashers or removing rust from restroom facilities.
Abrasive uses
* Buffing.
* Honing.
* Drilling.
* Grinding.
* Sanding.
* Polishing.
* Cutting.
* Sharpening.
Answer:
Missing numbers are 3,11,13, 15,17,19, 23,27,29 and wrong are 6,68
Given that,
Frequency emitted by the bat, f = 47.6 kHz
The speed off sound in air, v = 413 m/s
We need to find the wavelength detected by the bat. The speed of a wave is given by formula as follows :

or

So, the bat can detect small objects such as an insect whose size is approximately equal to the wavelength of the sound the bat makes i.e. 8.67 mm.
Heat required to raise the temperature of a given system is

here we know that
m = mass
s = specific heat capacity
= change in temperature
now as we know that
mass of wood = 5 kg
mass of aluminium pan = 2 kg
change in temperature = 45 - 20 = 25 degree C
specific heat capacity of wood = 1700 J/kg C
specific heat capacity of aluminium = 900 J/kg C
now here we will find the total heat to raise the temperature of both




So heat required to raise the temperature of the system is 257500 J