Answer:
λ = 5.85 x 10⁻⁷ m = 585 nm
f = 5.13 x 10¹⁴ Hz
Explanation:
We will use Young's Double Slit Experiment's Formula here:

where,
λ = wavelength = ?
Y = Fringe Spacing = 6.5 cm = 0.065 m
d = slit separation = 0.048 mm = 4.8 x 10⁻⁵ m
L = screen distance = 5 m
Therefore,

<u>λ = 5.85 x 10⁻⁷ m = 585 nm</u>
Now, the frequency can be given as:

where,
f = frequency = ?
c = speed of light = 3 x 10⁸ m/s
Therefore,

<u>f = 5.13 x 10¹⁴ Hz</u>
Answer:
No concave lens cannot be used to make hand lens because in hand Lens we use convex lens so as to converge the rays of the light After refraction and helps to produce a magnified image of an object.
Hope it will help you :)❤
Herz is a measurement for how many cycles of the wave occur per second, which in this case is 261. the period is the time it takes to complete 1 cycle, so if 261 cycles occur per second, one cycle occurs every 1/261 seconds
Answer:
the normal force
Explanation:
The free-body diagram represents all the forces acting on an object. In this example, there are four forces acting on the box: an applied force, the friction (which always act opposite to the applied force), the weight of the box (which is always downward), and the normal force.
The normal force is the reaction force exerted by the surface on which the box is moving on the box, and this reaction force is always opposite to the force exerted by the box on the surface. Since the latter is downward, it means that the normal force must be upward, so in the diagram it is wrong.