Answer:
1. the force which can be felt or act only when two objects are in contact is known as contact force.
for example: frictional force, muscular force,
tension, air resistance .
2. the force which can be felt or act even when two objects are in contact or not is known as non-contact force.
for example: magnetic force, gravitational force, electrostatic force.
I think A is the correct answer
Answer:
The correct option is : Their atoms have eight electrons in their valence shells, so noble gases are very unreactive.
Explanation:
The octet rule state that atoms tend to complete their last energy levels with eight electrons, and that this configuration make them very stable and unreactive.
Noble gases are characterized as unreactive atoms, and this is associated with the fact that they have a complete valence shell, it means that they have eight electrons on it (they follow the octet rule).
Atoms with less electrons on their valence shells tend to react with another atom, forming bonds, to complete their valence shells (with eight electrons).
Answer:
Explanation:
Given
side of square shape 
Electric flux 
Permittivity of free space 
Flux is given by

where E=electric field strength
A=area
=Angle between Electric field and area vector



and Electric field by a uniformly charged sheet is given by

where
=charge density


Explanation:
v=?, u=0, a=?, S=22m.
Using the formula, S=ut+½at²
22={0×5}+(½.a.5²)
22=½.a.5²
a=44/25 = 1.76m/s².
Therefore, net force = work done = ma = 48×1.76 = 84.48N.
therefore, power = work done/time = 84.48/5 = 16.896W.
hope this helps you.