Answer: C
X = Displacement of the spring
Hooke's law: It states that the applied force F is proportional to the displacement of spring .
F ∝ x
Where, x = displacement of spring in meters
F = force, measured in Newtons
In another words The force F is equal to the constant K times the disparagement.
F = k.x
Where k is constant and it depends on elastic material.
Spring has restorative force.
If the spring moves in opposite direction then,
F = - k.x
A negative sign indicates that the spring resists and force is to the left. The compression of the spring is greater than the restoring force.
Example: A mass 'm' stretches a spring at a displacement x.
Answer: 4 times grease
Explanation: Force F= C · q1·q2/r². C = Coulomb's constant.
If charges double you have 2q1 and 2q2.
Answer:

Explanation:
<u>Conservation of Momentum
</u>
The total momentum of a system of two particles is

Where m1,m2,v1, and v2 are the respective masses and velocities of the particles at a given time. Then, the two particles collide and change their velocities to v1' and v2'. The final momentum is now

The momentum is conserved if no external forces are acting on the system, thus

Let's put some numbers in the problem and say



120=120
It means that when the particles collide, the first mass returns at 6 m/s and the second continues in the same direction at 28 m/s
Answer:
weight at height = 100 N .
Explanation:
The problem relates to variation of weight due to change in height .
Let g₀ and g₁ be acceleration due to gravity , m is mass of the object .
At the surface :
Applying Newton's law of gravitation
mg₀ = G Mm / R²
At height h from centre
mg₁ = G Mm /h²
Given mg₀ = 400 N
400 = G Mm / R²
400 = G Mm / (6400 x 10³ )²
G Mm = 400 x (6400 x 10³ )²
At height h from centre
mg₁ = 400 x (6400 x 10³ )²/ ( 2 x 6400 x 10³)²
= 400 / 4
= 100 N .
weight at height = 100 N
So we want to know how can we detect infrared rays without an instrument. Infrared rays or heat, are a part of electromagnetic spectrum. We have specialized nerve cells in our skin called thermoreceptors that can detect differences in temperature that are produced by infrared part of EM spectrum.