Jamie pushes a book off a table. The push is an example of a contact force because A. Jamie used energy. B. Jamie had to touch t
2 answers:
You might be interested in
Answer:
the wavelength λ of the light when it is traveling in air = 560 nm
the smallest thickness t of the air film = 140 nm
Explanation:
From the question; the path difference is Δx = 2t (since the condition of the phase difference in the maxima and minima gets interchanged)
Now for constructive interference;
Δx=
replacing ;
Δx = 2t ; we have:
2t =
Given that thickness t = 700 nm
Then
2× 700 = --- equation (1)
For thickness t = 980 nm that is next to constructive interference
2× 980 = ----- equation (2)
Equating the difference of equation (2) and equation (1); we have:'
λ = (2 × 980) - ( 2× 700 )
λ = 1960 - 1400
λ = 560 nm
Thus; the wavelength λ of the light when it is traveling in air = 560 nm
b)
For the smallest thickness
∴
Thus, the smallest thickness t of the air film = 140 nm
Answer:
The recoil velocity is 0.2687 m/s.
Explanation:
∵ The person is sitting on an icy surface , we can assume that the surface is frictionless.
∴ There is no force acting acting on the person and book as a system in horizontal direction.
Hence , momentum is conserved for this system in horizontal direction of motion.
If 'i' and 'f' be the initial and final states of this system , then by principle of conservation of momentum(p) -
=
System initially is at rest
∴=0
∴ From the above 2 equations
=0
We know that ,
Momentum(p)=Mass of the body(m)×velocity of the body(v)
Let and
be the mass of the person and the book respectively and
and
be the final velocities of the person and book respectively.
∴=
+
=0
From the question ,
= 74.9 kg
= 2.44 kg
= 8.25 m/s
Substituting these values in the above equation we get ,
(74.9 × )+ (2.44×8.25) = 0
∴ = - 0.2687 m/s (Negative sign suggests that the motion of the person is opposite to that of the book)
∴ The recoil velocity is 0.2687 m/s.