Qué es el espectro electromagnético

When falling through the air, which of the following objects will hit the ground first?

Pavel [41]

Answer:

a penny

Explanation:

5 0

4 years ago

Read 2 more answers

True or false?

Ksju [112]

1. False

Explanation: it's exactly the opposite. In fact, Lenz's law states that the induced current and the induced emf in a conductor are generated in such a direction that opposes to the change in magnetic flux through the coil. This is summarized by the negative sign in the Faraday's Newmann Lenz law:

$\epsilon= -\frac{d\Phi }{dt}$

where $\epsilon$ is the emf induced and $\frac{d\Phi}{dt}$ is the rate of change of magnetic flux through the coil.

Lenz's law is a consequence of the law of conservation of energy. In fact, we have:

- If the magnetic flux through a coil is increasing, then the induced current has a direction such that the magnetic field generated by the coil is opposite to the direction of the external magnetic field, in order to decrease the total flux

- If the magnetic flux through a coil is decreasing, then the induced current has a direction such that the magnetic field generated by the coil is in the same direction as the external field, in order to increase the total flux

2. False

Explanation: the magnetic flux through a surface is given by

$\Phi = BA cos \theta$

where

B is the magnitude of the magnetic field

A is the surface area

$\theta$ is the angle between the direction of B and the normal vector to the surface

As we see, the magnetic flux depends not only on B and A, but also on the orientation of the coil with respect to the magnetic field.

3. False

Explanation:

- Sound waves are mechanical waves: mechanical waves are waves consisting of oscillations of the particles in a medium. Due to their nature, therefore, mechanical waves can propagate only in the presence of a medium

- Electromagnetic waves are NOT mechanical waves: they consist of oscillations of electric and magnetic fields, in a direction perpendicular to the direction of propagation of the wave. Since em waves are not mechanical waves, they do NOT need a medium to propagate, since they can also travel through a vacuum; therefore the original statement is false.

5 0

3 years ago

An average human weighs about 600 N

NemiM [27]

Answer:

The distance between them, x = 5809.47 m

Explanation:

Given,

The average weight of a human, w = 600 N

The charge carried by the humans, q = 1.5 C

If 600 N of force acts between two opposite charges, the distance between the charges can be derived from the Coulomb's laws of force,

<em> $F=\frac{1}{4\pi\epsilon_{0}}\frac{qq}{x^{2}}$ </em>

Where,

$\frac{1}{4\pi\epsilon_{0}}$ = 9 x 10⁹ N m² C⁻²

Therefore

x² = 9 x 10⁹ X 1.5² / 600

= 33750000

x = 5809.46 m

Hence, the distance between the humans should be, x = 5809.47 m

4 0

3 years ago

A moving small car has a head-on collision with a large stationary truck 7.3 times the mass of the car. Which statement is true

san4es73 [151]

Answer:

The car would speed off 2x's as fast as the speed of the heavy truck provided the the collision is an elastic collision where there's no or little friction occurring within the scenario.

Explanation:

Newton's law proves that an object with a greater mass can move objects of lesser mass at greater distances and speed.

7 0

3 years ago

A 150 g ball and a 240 g ball are connected by a 33-cm-long, massless, rigid rod. The balls rotate about their center of mass at

stira [4]

Answer:

v= 3.18 m/s

Explanation:

Given that

m= 150 g = 0.15 kg

M= 240 g = 0.24 kg

Angular speed ,ω = 150 rpm

The speed in rad/s

$\omega =\dfrac{2\pi N}{60}$

$\omega =\dfrac{2\pi \times 150}{60}$

ω = 15.7 rad/s

The distance of center of mass from 150 g

$r=\dfrac{150\times 0+240\times 33}{150+240}\ cm$

r= 20.30 cm

The speed of the mass 150 g

v= ω r

v= 20.30 x 15.7 cm/s

v= 318.71 cm/s

v= 3.18 m/s

6 0

3 years ago