The mathematical and proportional relationship between mL and 
said us that 
is equivalent to 1mL.
If the density is considered as the amount of mass per unit volume we will have to
here,
m = mass
V = Volume
Replacing we have that
As 
we have that the density in g/mL is,
Answer:
D. A zinc Zn contains 30 protons inside the nucleus and 30 electron outside the nucleus
This is a question on conservation of energy. That is,
mgh + KE1 = KE2
mgh +1/2mv1^2 = 1/2mv2^2
gh + 1/2v1^2 = 1/2v2^2
Where, h = 0.2 m, v1 =3.04 m/s
Therefore,
v2 = Sqrt [2(gh+1/2v1^2)] = Sqrt [2(9.81*0.2 + 1/2*3.04^2)] = 7.26 m/s
Now, Volumetric flow rate, V/time, t = Surface area, A*velocity, v
Where,
V = Av = πD^2/4*3.04 = π*(2.51/100)^2*1/4*3.04 = 1.504*10^-3 m^3/s
At 0.2 m below,
V = 1.504*10^-3 m^3/s = A*7.26
A = (1.504*10^-3)/7.26 = 2.072*10^-4 m^2
But, A = πr^2
Then,
r = Sqrt (A/π) = Sqrt (2.072*10^-4/π) = 0.121*10^-3 m
Diameter = 2r = 0.0162 m = 1.62 cm
Diffraction means spreading out of waves that has the same wavelength as the size of the gap. Sound waves have high wavelength and so it diffracts\spreads out and enables anyone to hear your voice from anywhere outside the room.
For inside the room, the sound waves doesn't actually diffract. They collide with the air particles, causing a series of compressions and rarefactions which spreads out in the air particles and anyone can hear your voice.
Air is the medium for the sound waves to travel.
I believe they are called nonohmic materials. According to ohms law the current trough a current carrying conductor is directly proportional to the potential difference (voltage) at a constant resistance. Non-ohmic conductors or materials are those materials that do not obey the ohms law, their resistance increases as the current increases. Ohmic materials are those that obeys the ohms law such that the voltage and current are proportional- doubling the potential difference doubles the current.
