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2 years ago

Reflecting telescopes are popular because they're

2 answers:

Crank2 years ago

6 0

C. easier to build than a refracting telescope

Big mirrors used in reflecting telescopes are easier and cheaper to make than big lenses which would cost more because of the quality of glass required to make refracting telescopes

nasty-shy [4]2 years ago

6 0

C. easier to build than a refracting telescope.

You might be interested in

An electron in the n = 5 level of an h atom emits a photon of wavelength 1282.17 nm. to what energy level does the electron move

lions [1.4K]

This is an interesting (read tricky!) variation of Rydberg Eqn calculation.
Rydberg Eqn: 1/λ = R [1/n1^2 - 1/n2^2]
Where λ is the wavelength of the light; 1282.17 nm = 1282.17×10^-9 m
R is the Rydberg constant: R = 1.09737×10^7 m-1
n2 = 5 (emission)
Hence 1/(1282.17 ×10^-9) = 1.09737× 10^7 [1/n1^2 – 1/25^2]
Some rearranging and collecting up terms:
1 = (1282.17 ×10^-9) (1.09737× 10^7)[1/n2 -1/25]
1= 14.07[1/n^2 – 1/25]
1 =14.07/n^2 – (14.07/25)
14.07n^2 = 1 + 0.5628
n = √(14.07/1.5628) = 3

8 0

3 years ago

Read 2 more answers

Helicopter blades withstand tremendous stresses. In addition to supporting the weight of a helicopter, they are spun at rapid ra

BabaBlast [244]

Explanation:

It is given that,

Length of the helicopter, l = 3.1 m

The helicopter rotates, the length of helicopter will become the radius of circular path, r = 3.1 m

Angular speed of the helicopter, $\omega=280\ rev/min=29.32\ rad/s$

(a) The centripetal acceleration in terms of angular velocity is given by :

$a_c=r\times \omega^2$

$a_c=3.1\times (29.32)^2$

$a_c=2664.95\ m/s^2$

(b) Let v is the linear speed of the tip. The relation between the linear and angular speed is given by :

$v=r\times \omega$

$v=3.1\times 29.32$

v = 90.89 m/s

$\dfrac{v_{tip}}{v_{sound}}=\dfrac{90.89}{340}=0.267$

Hence, this is the required solution.

4 0

3 years ago

A 48.9 kg meteor is moving in outer space. If a 8.6 N force is applied opposite the direction of motion, what is the deceleratio

nalin [4]

Answer:

The deceleration is 0.18 m/s²

Explanation:

Hi there!

Using Newton´s second law, we can calculate the deceleration:

∑F = m · a

Where:

∑F = the sum of all forces in a given direction.

m = mass of the object.

a = acceleration.

Solving for a:

∑F/m = a

The only force acting on the meteor is the applied force of 8.6 N. So, the acceleration will be:

8.6 N / 48.9 kg = a

a = 0.18 m/s²

The deceleration is 0.18 m/s² or, in other words, the acceleration is -0.18 m/s²

Have a nice day!

3 0

2 years ago

WGVU-AM is a radio station that serves the Grand Rapids, Michigan area. The main broadcast frequency is 1480kHz. At a certain di

Yuki888 [10]

Answer:

$\lambda = 202.7 \ m$

$w = 9.3 *10^{6} \ rad/s$

$k = 0.031 m^{-1}$

$E_{max} = 9.0 *10^{-3} \ V/m$

Explanation:

From the question we are told that

The frequency of the radio station is $f= 1480 \ kHz = 1480 *10^{3}\ Hz$

The magnitude of the magnetic field is $B = 3.0* 10^{-11} \ T$

Generally the wavelength is mathematically represented as

$\lambda = \frac{c}{f}$

Here c is the speed of light with value $c = 3.0 *10^{8} \ m/s$

$\lambda = \frac{3.0 *10^{8}}{ 1480 *10^{3}}$

=> $\lambda = 202.7 \ m$

Generally the angular frequency is mathematically represented as

$w = 2 \pi * f$

=> $w = 2 * 3.142 * 1480 *10^{3}$

=> $w = 9.3 *10^{6} \ rad/s$

Generally the wave number is mathematically represented as

=> $k = \frac{2 \pi }{\lambda}$

=> $k = \frac{2 * 3.142 }{ 202.7}$

=> $k = 0.031 m^{-1}$

Generally the amplitude of the electric field at this distance from the transmitter is mathematically represented as

$E_{max} = c * B$

=> $E_{max} = 3.0 *10^{8} * 3.0* 10^{-11}$

=> $E_{max} = 9.0 *10^{-3} \ V/m$

3 0

2 years ago

Drawing Conclusions Suppose you take a short piece of wire that is not attached to anything and move it up and down in a magneti

Ulleksa [173]

Answer: No. Circuit should be closed.

Explanation:

A changing magnetic field induces emf in a circuit which is placed in it. This induced emf causes current to flow through it. This is given by Faraday's law which states that induced emf results due to rate of change of magnetic flux.

$e = \frac{-d\phi}{dt}= -\frac {dB A} {dt}$

Current flows only through a closed circuit. Thus, when a wire is moved up and down in a magnetic field, it will not induce emf because the wire does not form a loop. It is an open circuit.

4 0

3 years ago

Read 2 more answers