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3 years ago

Which description correctly summarizes how an electric motor causes an axle to turn?

Physics

1 answer:

alexira [117]3 years ago

6 0

Answer:

B on edge

Explanation:

the piles of the magnetic field generated around the armature are attracted to the opposite poles of the permanent magnent. As the opposite poles align, the commutator reverses the current direction so like poles are aligned and the armature continues to spin

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You are traveling at 14 m/s for 20 seconds. What is your displacement?

enyata [817]

Velocity = 14 m/s

Time = 20 s

Displacement = Velocity×Time = (14×20) m = 280 m

The displacement is 280 m towards the direction of motion.

5 0

3 years ago

Read 2 more answers

A child\'s top is held in place, upright on a frictionless surface. The axle has a radius of r = 2.96 mm. Two strings are wrappe

sladkih [1.3K]

Answer:

Explanation:

Given

radius r=2.96 mm

Tension T=2.4 N

time taken=0.74 s

Let $\alpha$ be the angular acceleration

$2 T\times r=I\times \alpha$

$2\times 2.4\times 2.96\times 10^{-3}=0.5\times m\times (2.96\times 10^{-3})^2\times \alpha$

$\alpha =\frac{4\times 2.4}{m\times 2.96\times 10^{-3}}$

$\alpha =\frac{3.24\times 10^3}{m} rad/s^2$

$\omega =\omega _0+\alpha \cdot t$

$\omega =0+\frac{3.24\times 10^3}{m}\times 0.74$

$\omega =\frac{2.4\times 10^3}{m} rad/s$

Angular momentum

$L=I\omega$

$L=0.5\times mr^2\times \omega$

$L=0.5\times m\times (2.96\times 10^{-3})^2\times \frac{2.4\times 10^3}{m}$

$L=0.01051 kg-m^2/s$

4 0

3 years ago

Why can’t we see black holes? Question 11 options: A.Because they don't want to be seen. B.Because the sun is too far away from

Vika [28.1K]

We can't see black holes because D) no light can get out

Explanation:

Black holes are the result of the gravitational collapse of a supermassive star.

The life of a supermassive star ends with a huge explosion, called supernova, that leaves behing a super-dense core called black hole.

Black holes are the most dense objects of the universe, having a huge mass in a super small size. For this reason, the gravitational force exerted by a black hole in its proximity is so strong that even light is not able to escape from the gravitational field. For this reason, light from a black hole is not able to reach us, and so we are not able to see these objects.

The "edge" of space beyond which light remains "trapped" inside the black hole is called event horizon, and no object can escape this region of space.

The radius of the event horizon of a black hole is called Schwarzschild radius and it is given by:

$r=\frac{2GM}{c^2}$