Answer:
The diameter is 0.000056 m
Explanation:
Lets explain the relation between the meter and the micrometer
1 Meter is equal to 1000000 (one million) micrometers
1 micrometer = 
The symbol of the meter is m
The symbol of micrometer is μm
A human hair is approximately 56 µm in diameter
We need to express this diameter in meter
To do that we divide this number by 1,000,000 or multiply it by 
→ 
56 µm = 0.000056 m
→ OR
→ 
→ 56 µm = 0.000056 m
<em>The diameter is 0.000056 m</em>
Answer:
<h3> 3.057m</h3>
Explanation:
According to law of gravitation;
F = GMm/d²
G is the universal gravitation
M and m are the masses
d is the distance between the masses
d² = GMm/F
d² = 6.67408 × 10-11 *3000*7000/0.0015
d² = 140.15568*10^-5/0.0015
d² = 1.4016*10^-3/0.0015
d² = 1.4016*10^-3/1.5*10^-3
d² = 0.9344*10
d² = 9.344
d = √9.344
d = 3.057m
Hence the distance between the two objects is 3.057m
Answer: a) 274.34 nm; b) 1.74 eV c) 1.74 V
Explanation: In order to solve this problem we have to consider the energy balance for the photoelectric effect on tungsten:
h*ν = Ek+W ; where h is the Planck constant, ek the kinetic energy of electrons and W the work funcion of the metal catode.
In order to calculate the cutoff wavelength we have to consider that Ek=0
in this case h*ν=W
(h*c)/λ=4.52 eV
λ= (h*c)/4.52 eV
λ= (1240 eV*nm)/(4.52 eV)=274.34 nm
From this h*ν = Ek+W; we can calculate the kinetic energy for a radiation wavelength of 198 nm
then we have
(h*c)/(λ)-W= Ek
Ek=(1240 eV*nm)/(198 nm)-4.52 eV=1.74 eV
Finally, if we want to stop these electrons we have to applied a stop potental equal to 1.74 V . At this potential the photo-current drop to zero. This potential is lower to the catode, so this acts to slow down the ejected electrons from the catode.
