Answer:
option A
Explanation:
given,
compression for lower setting = x
work done to compress in lower setting = 5 J
compression in higher setting, x' = 2 x
work done in higher setting = ?
Work done in compression of spring at lower setting

............(1)
Work done in compression of spring at higher setting




from equation (1)

W' = 20 J
Work take for the higher setting is equal to 20 J
Hence, the correct answer is option A
Answer:
of the velocity of a full size plane in the air
Explanation:
Given that,
Charge 1, 
Charge 2, 
Distance between charges, r = 0.0209 m
1. The electric force is given by :


F = -492.95 N
2. Distance between two identical charges, 
Electric force is given by :




Hence, this is the required solution.