A syringe has a fine needle with an inside diameter of 109μm. The barrel has a diameter of 2.22cm and is filled with water. Calculate the velocity of water as it squirts horizontally from the needle if you apply a force of 3.24N onto the plunger. (Hint: you may approximate the area of the barrel to be much larger than the area of the needle).

the velocity of water as it squirts horizontally from the needle is 4.09196 m/s

Explanation:

Given that;

inside diameter = 109μm

barrel diameter = 2.22 cm so r = 1.11 cm = 0.0111 m

force fair = 3.24 N

We know that the inside diameter is neglected; from the Bernoulli's equation

so

P_inside + 1/2pv²_inside + egy_inside = P_outside + 12pv²_outside + egy_outside

p_inside - p_outside = 1/2e_airv²outside = Fair / Abannel

Fair = 1/2painv²outside . Abannel

therefore

3.24 = 1/2(1000) v²outside (πr²)

3.24 = 1/2(1000) v²outside (π × (0.0111)²

3.24 = 0.1935 v²_outlet

v²_outlet = 3.24 / 0.1934

v²_outlet  = 16.7441

v_outlet = √16.7441

v_outlet  = 4.09196 m/s

Therefore the velocity of water as it squirts horizontally from the needle is 4.09196 m/s

graph question answered .. you think better when you are relaxed and happy

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia