Complete Question
One day, after pulling down your window shade, you notice that sunlight is passing through a pinhole in the shade and making a small patch of light on the far wall. Having recently studied optics in your physics class, you're not too surprised to see that the patch of light seems to be a circular diffraction pattern. It appears that the central maximum is about 2 cm across, and you estimate that the distance from the window shade to the wall is about 5 m.
Required:
Estimate the diameter of the pinhole.
Answer:
The diameter is 
Explanation:
From the question we are told that
The central maxima is 
The distance from the window shade is 
The average wavelength of the sun is mathematically evaluated as
Generally the visible light spectrum has a wavelength range between 400 nm to 700 nm
So the initial wavelength of the sun is 
and the final wavelength is 
Substituting this into the above equation
The diameter is evaluated as
substituting values
False
If all other factors, such as medium, are kept the same, longitudinal waves tend to be stronger.
The answers are B, C, E and F.
Atoms from an element is mostly made of protons, neutrons, and electrons. Proton numbers are like a class number for each element. Each element has their own and they're all different. And the number of protons are equal to the number of electrons. Therefore, B is correct.
Isotopes. It's different atoms from a same element that has the same number of protons but different number of neutrons. For example in hydrogen, there's 3 Isotopes for hydrogen. Therefore, C is correct.
Again, proton for the same element is never changed, even if they're different Isotopes. So, E is correct.
Isotopes, again, different elements may have different Isotopes. Some has only 1, others may have a few or more. So, F is correct too.
Answer:
50 lb
Explanation:
Given,
The weight of astronaut's life support backpack on Earth (w) = 300 lb
Acceleration due to gravity on Earth (g) = 9.8 m/s²
Acceleration due to gravity on Moon = g'
We know that weight of an object on Earth is,
Similarly, weight on Moon will be
Thus the astronaut's life support backpack will weigh 50 lb on Moon.
Answer:
1. t = 0.0819s
2. W = 0.25N
3. n = 36
4. y(x , t)= Acos[172x + 2730t]
Explanation:
1) The given equation is
The relationship between velocity and propagation constant is
v = 15.87m/s
Time taken, 
t = 0.0819s
2)
The velocity of transverse wave is given by
mass of string is calculated thus
mg = 0.0125N
m = 0.00128kg
0.25N
3)
The propagation constant k is
hence
0.036 m
No of wavelengths, n is
n = 36
4)
The equation of wave travelling down the string is
![y(x, t)=Acos[kx -wt]\\\\becomes\\\\y(x , t)= Acos[(172 rad.m)x + (2730 rad.s)t]](https://tex.z-dn.net/?f=y%28x%2C%20t%29%3DAcos%5Bkx%20-wt%5D%5C%5C%5C%5Cbecomes%5C%5C%5C%5Cy%28x%20%2C%20t%29%3D%20Acos%5B%28172%20rad.m%29x%20%2B%20%282730%20rad.s%29t%5D)
![without, unit\\\\y(x , t)= Acos[172x + 2730t]](https://tex.z-dn.net/?f=without%2C%20unit%5C%5C%5C%5Cy%28x%20%2C%20t%29%3D%20Acos%5B172x%20%2B%202730t%5D)
