Answer:
a)
= 3,375 cm
, b) f₀ = 77.625 cm
Explanation:
The magnification of a telescope is, to see at the far point of vision (infinity image)
m = - f₀ / 
The length of the tube is
L = f₀ + 
a) The focal length of the eyepiece
L = - m
+ 
L =
(1-m)
= L / (1-m)
Let's calculate
= 81.0 / (1 - (-23.0)
= 3,375 cm
b) the focal length of the target
f₀ = -m
f₀ = 23 (3.68)
f₀ = 77.625 cm
The equation to be used is the derived formulas for rectilinear motion at a constant acceleration. The formula for acceleration is
a = (v - v₀)/t
where
v and v₀ are the initial and final velocities, respectively
t is the time
a is the acceleration
Since it started from rest, v₀ = 0. Using the formula:
0.15 m/s² = (v - 0)/[2 minutes*(60 s/1 min)]
Solving for v,
v = 18 m/s
This is a classic example of conservation of energy. Assuming that there are no losses due to friction with air we'll proceed by saying that the total energy mus be conserved.

Now having information on the speed at the lowest point we can say that the energy of the system at this point is purely kinetic:

Where m is the mass of the pendulum. Because of conservation of energy, the total energy at maximum height won't change, but at this point the energy will be purely potential energy instead.

This is the part where we exploit the Energy's conservation, I'm really insisting on this fact right here but it's very very important, The totam energy Em was

It hasn't changed! So inserting this into the equation relating the total energy at the highest point we'll have:

Solving for h gives us:

It doesn't depend on mass!
Answer:
They contain iron.
Explanation:
Iron is made of metal and magnets attract to metal Iron.
If the separation between the openings in a laser is increased, then the distance between the interference fringes decreases
<h3>What is Interference fringe ?</h3>
Interference fringe refers to bands caused by different lights which can be found in phase or not each other.
- Distances between laser fringes are short which is due to light wavelength.
- The interference fringes can be estimated by knowing slit separation and wavelength.
In conclusion, if the separation between the openings in a laser is increased, then the distance between the interference fringe decreases
Learn more about Interference fringe here:
brainly.com/question/14264436
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