(a) 5.66 m/s
The flow rate of the water in the pipe is given by
where
Q is the flow rate
A is the cross-sectional area of the pipe
v is the speed of the water
Here we have
the radius of the pipe is
r = 0.260 m
So the cross-sectional area is
So we can re-arrange the equation to find the speed of the water:
(b) 0.326 m
The flow rate along the pipe is conserved, so we can write:
where we have
and where 
is the cross-sectional area of the pipe at the second point.
Solving for A2,
And finally we can find the radius of the pipe at that point:
Explanation:
Weak nuclear force:
The interaction between the subatomic particles is called weak nuclear force.
The weak nuclear force is one of the four fundamental forces.
The weak nuclear force is effective at very short distance.
The range and relative strength of weak nuclear force is 10⁻¹⁸ m and 10²⁵ with respect to gravitational force respectively
Deuterium is formed due to the fusion of protons and neutrons under the action the weak force.
Example : Beta decay
Electromagnetic force:
The interaction between the charged particles is called electromagnetic force.
The electromagnetic force is one of the four fundamental forces.
The electromagnetic force is effective at long range distance.
The range and relative strength of electromagnetic force is infinity and 10³⁶ with respect to gravitational force respectively
Example : light
The primary colors of light are red, blue and green.
There are the pigments like yellow, magenta and cyan that are the mixture of two primary colors.
For example, magenta is a mixture of red and blue color. Thus, it reflects the red and blue color. Also, magneta absorbs the green color.
These type of colors that reflects two primary colors and absorb one color are known as secondary pigments.
Hence, 2nd option is the correct answer.
