Answer:
B is the best answer for this question
The block moves with constant velocity: for Newton's second law, this means that the resultant of the forces acting on the block is zero, because the acceleration is zero.
We are only concerned about the horizontal direction, and there are only two forces acting along this direction: the force F pushing the block and the frictional force
acting against the motion. Since their resultant must be zero, we have:
The frictional force is
where
is the coefficient of kinetic friction
is the weight of the block.
Substituting these values, we find the magnitude of the force F:
Look first for the relation between deBroglie wavelength (λ) and kinetic energy (K):
K = ½mv²
v = √(2K/m)
λ = h/(mv)
= h/(m√(2K/m))
= h/√(2Km)
So λ is proportional to 1/√K.
in the potential well the potential energy is zero, so completely the electron's energy is in the shape of kinetic energy:
K = 6U₀
Outer the potential well the potential energy is U₀, so
K = 5U₀
(because kinetic and potential energies add up to 6U₀)
Therefore, the ratio of the de Broglie wavelength of the electron in the region x>L (outside the well) to the wavelength for 0<x<L (inside the well) is:
1/√(5U₀) : 1/√(6U₀)
= √6 : √5
Option B The thickness of the central portion of a thin conveying lens can be determined very accurately by using a micrometer screw gauge.
<h3>What can be measured using a micrometer screw gauge?</h3>
One micrometer of thickness can be measured with a micron micrometre screw gauge. A Use of Micrometer Screw Gauge as like example Upon turning the screw of the micrometer screw gauge four times, a 2 mm space is covered.
<h3>What purposes does a micrometer serve?</h3>
A tool known as a micrometer is used to measure solid objects’ lengths, thicknesses, and other dimensions precisely and linearly.
<h3>What is the micrometer screw gauge’s SI unit?</h3>
The SI symbol m is also known as a micron, which is an SI-derived unit of length equaling 1106 meters, where 106 is the SI standard prefix for the prefix “micro-.” A micrometer is one-millionth of a meter.
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Answer:
2Ω
Explanation:
If a 18Ω resistance is cut into three equal parts each of the resistance will be 18Ω/3 = 6Ω
Equivalent ratio in parallel is expressed as:
1/R = 1/6 + 1/6 + 1/6
1/R = 3/6
Cross multiply
3R = 6
R = 6/3
R = 2Ω
Hence the required equivalent resistance is 2Ω
