Answer:
(d) 2840 A
Explanation:
Threshold frequency can be be calculated using expresion below
(λ)= hc/ Φ
(λ) sodium/ (λ)tungsten = Φtungsten/ Φsodium
But (λ) sodium is given as 5460 A,
Φsodium = 2.3 eV
Φtungsten= 4.4 eV
If we substitute the values we can find
(λ)tungsten.
(λ)tungsten= [(λ) sodium × Φsodium]/ Φtungsten
=( 5460× 2.3)/4.4
= 2854A
Hence, threshold wavelength of tungsten is 2854A
Option (E) is correct
Neither (they arrive together)
<u>Explanation:</u>
Neither of the cylinders gets to the bottom first, they both will arrive together. Every object can gain speed with time if it is pushed, it is called the acceleration of that object. It the acceleration that decides which object reaches the bottom first.
Acceleration = I / mr^2.
In the case of both the cylinders, the acceleration will be the same, with the same acceleration they will reach the bottom at the same time.
Frictional force is reduced in smooth surfaces but is large in rough surfaces.
<h3>What is Force?</h3>
Force is defined as an agent which causes a change in the motion or state of an object.
Forces are of two types:
- Contact forces and
- Non-contact forces
Contact forces include frictional force.
Frictional forces refers to the force which acts between two surfaces in contact by opposing the relative motion of one over the other
Frictional force depends on the nature of surfaces in contact where rough surfaces produce greater frictional force than smooth surfaces.
Therefore, frictional force is reduced in smooth surfaces but is large in rough surfaces.
Learn more about frictional force at: brainly.com/question/23161460
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The correct answer is 30 j