Answer:
B. 6 cm
Explanation:
First, we calculate the spring constant of a single spring:

where,
k = spring constant of single spring = ?
F = Force Applied = 10 N
Δx = extension = 4 cm = 0.04 m
Therefore,

Now, the equivalent resistance of two springs connected in parallel, as shown in the diagram, will be:

For a load of 30 N, applying Hooke's Law:

Hence, the correct option is:
<u>B. 6 cm</u>
Answer:
The value of radiation pressure is
Pa
Explanation:
Given:
Intensity

Area of piece

From the formula of radiation pressure in terms of intensity,

Where
radiation pressure,
speed of light
We know value of speed of light,

Put all values in above equation,

Pa
Therefore, the value of radiation pressure is
Pa
Work done is the distance a force acts over.
So, the work done here is 9.0N * 3.0m = 27 J
Magnetism is the force exerted by magnets when they attract or repel each other. Magnetism is caused by the motion of electric charges. Every substance is made up of tiny units called atoms. Each atom has electrons, particles that carry electric charges.
B. 1520 is the difference between their weights.