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3 years ago

What does a light year measure

Physics

2 answers:

SVEN [57.7K]3 years ago

8 0

It’s used in measuring distance from earth with other celestial object. Hope this helps mark brainest

IRINA_888 [86]3 years ago

5 0

Light years measure the distance in space

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Refraction occurs when a wave

lesya692 [45]

Answer:

Explanation:

Did on a quiz and got it right

6 0

3 years ago

Read 2 more answers

Which material is more closely related to the styrofoam? a. heat exchanger b. diffuser c. insulator d. electrical conductor

nirvana33 [79]

The material that is more closely related to the Styrofoam insulator.

Styrofoam is the term that is used for polystyrene foam in a trademark form. It is a petroleum-based plastic.

Keeping something warm includes the stopping of the transfer of heat from one object to another. This is how insulation works.

Styrofoam is an insulator, which means it'll help keep the heat from the environment out of your cooler. However, you'll still need cooling agents (like ice packs) to make the cooler cold in the first place.

Styrofoam is usually made mostly of air, which means it is a poor conductor of heat, but an excellent convector. It traps the air in small pockets, which blocks the flow of heat energy. This reduces both conduction and convection and makes Styrofoam a good insulator.

To learn more about Styrofoam here

brainly.com/question/21369568

#SPJ4

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2 years ago

A DJ starts up her phonograph player. The turntable accelerates uniformly from rest, and takes t1 = 11.9 seconds to get up to it

Degger [83]

Answer:

a) $\omega_1=8.168\,rad.s^{-1}$

b) $n_1=7.735 \,rev$

c) $\alpha_1 =0.6864\,rad.s^{-2}$

d) $\alpha_2=4.1454\,rad.s^{-2}$

e) $t_2=1.061\,s$

Explanation:

Given that:

initial speed of turntable, $N_0=0\,rpm\Rightarrow \omega_0=0\,rad.s^{-1}$

full speed of rotation, $N_1=78 \,rpm\Rightarrow \omega_1=\frac{78\times 2\pi}{60}=8.168\,rad.s^{-1}$

time taken to reach full speed from rest, $t_1=11.9\,s$

final speed after the change, $N_2=120\,rpm\Rightarrow \omega_2=\frac{120\times 2\pi}{60}=12.5664\,rad.s^{-1}$

no. of revolutions made to reach the new final speed, $n_2=11\,rev$

(a)

∵ 1 rev = 2π radians

∴ angular speed ω:

$\omega=\frac{2\pi.N}{60}\, rad.s^{-1}$

where N = angular speed in rpm.

putting the respective values from case 1 we've

$\omega_1=\frac{2\pi\times 78}{60}\, rad.s^{-1}$

$\omega_1=8.168\,rad.s^{-1}$

(c)

using the equation of motion:

$\omega_1=\omega_0+\alpha . t_1$

here α is the angular acceleration

$78=0+\alpha_1\times 11.9$

$\alpha_1 = \frac{8.168 }{11.9}$

$\alpha_1 =0.6864\,rad.s^{-2}$

(b)

using the equation of motion:

$\omega_1\,^2=\omega_0\,^2+2.\alpha_1 .n_1$

$8.168^2=0^2+2\times 0.6864\times n_1$

$n_1=48.6003\,rad$

$n_1=\frac{48.6003}{2\pi}$

$n_1=7.735\, rev$

(d)

using equation of motion:

$\omega_2\,^2=\omega_1\,^2+2.\alpha_2 .n_2$

$12.5664^2=8.168^2+2\alpha_2\times 11$

$\alpha_2=4.1454\,rad.s^{-2}$

(e)

using the equation of motion:

$\omega_2=\omega_1+\alpha_2 . t_2$

$12.5664=8.168+4.1454\times t_2$

$t_2=1.061\,s$

4 0

3 years ago

Which device uses a rotating magnetic field to produce an electric current?

Kay [80]

The correct answer is C) a motor.
In particular, we are talking about an AC motor, which produces an alternating current. In an AC motor, a coil is immersed in a rotating magnetic field. Due to the motion of the magnetic field,the angle between the direction of the field and the surface enclosed by the coil changes. As a result, the magnetic flux through the coil changes over time (the magnetic flux is given by:
 $\phi=BAcos\theta$ 
where B is the intensity of the magnetic field, A is the area enclosed by the coil and $\theta$ is the angle between the direction of B and the perpendicular to the plane of the coil). For Faraday-Newmann-Lenz law, this change in flux induces an electromotive force (emf) into the coil, according to:
 $emf=- \frac{d \Phi}{dt}$ 
where the numerator is the variation of magnetic flux and dt is the time interval. This emf in the coil produced an electrical current in the circuit.

7 0

3 years ago

Read 2 more answers

A subway train accelerates from rest at one station at a rate of 1.30 m/s^2 for half of the distance to the next station, then d

Minchanka [31]

This problems a perfect application for this acceleration formula:

 Distance = (1/2) (acceleration) (time)² .

During the speeding-up half: 1,600 meters = (1/2) (1.3 m/s²) T²
During the slowing-down half: 1,600 meters = (1/2) (1.3 m/s²) T²

Pick either half, and divide each side by 0.65 m/s²:

 T² = (1600 m) / (0.65 m/s²)

 T = square root of (1600 / 0.65) seconds

Time for the total trip between the stations is double that time.

 T = 2 √(1600/0.65) = 99.2 seconds (rounded)

7 0

3 years ago