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3 years ago

The illuminance On a surface is six lux and the surface is 4 meters from the light source what is the intensity of the source

Physics

1 answer:

Liula [17]3 years ago

5 0

Answer : 96 candelas

Explanation : Luminous intensity is a quantity of light that is emitted by a light source with a solid angle in a particular direction.

We know the formula of luminous intensity

Luminous intensity = illuminance x distance from light source

$L_{v} = E_{v}\times d^{2}$

$L_{v} = 6\times 16\ candelas$

$L_{v} = 96\ candelas$

So, the intensity of the source will be 96 candelas.

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Shtirlitz [24]

Answer:

It's an example of velocity.

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3 years ago

A copper sphere was moving at 40 m/s when it hit another object. This caused all of the KE to be converted into thermal energy f

USPshnik [31]

Answer:

Temperature increase = 2.1 [C]

Explanation:

We need to identify the initial data of the problem.

v = velocity of the copper sphere = 40 [m/s]

Cp = heat capacity = 387 [J/kg*C]

The most important data given is the fact that when the shock occurs kinetic energy is transformed into thermal energy, therefore it will have to be:

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3 years ago

An average human weighs about 600 N. If two such generic humans each carried 1.5 coulomb of excess charge, one positive and one

MakcuM [25]

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Explanation:

6 0

3 years ago

What does the rotational speed of the ring module have to be so that an astronaut standing on the outer rim of the ring module f

Usimov [2.4K]

Complete question:

In the movie The Martian, astronauts travel to Mars in a spaceship called Hermes. This ship has a ring module that rotates around the ship to create “artificial gravity” within the module. Astronauts standing inside the ring module on the outer rim feel like they are standing on the surface of the Earth. (The trailer for this movie shows Hermes at t=2:19 and demonstrates the “artificial gravity” concept between t= 2:19 and t=2:24.)

Analyzing a still frame from the trailer and using the height of the actress to set the scale, you determine that the distance from the center of the ship to the outer rim of the ring module is 11.60 m

What does the rotational speed of the ring module have to be so that an astronaut standing on the outer rim of the ring module feels like they are standing on the surface of the Earth?

Answer:

The rotational speed of the ring module have to be 0.92 rad/s

Explanation:

Given;

the distance from the center of the ship to the outer rim of the ring module r, = 11.60 m

When the astronaut standing on the outer rim of the ring module feels like they are standing on the surface of the Earth, then their centripetal acceleration will be equal to acceleration due to gravity of Earth.

Centripetal acceleration, a = g = 9.8 m/s²

Centripetal acceleration, a = v²/r

But v = ωr

a = g = ω²r

$\omega = \sqrt{\frac{g}{r}} = \sqrt{\frac{9.8}{11.6} } = 0.92 \ rad/s$

Therefore, the rotational speed of the ring module have to be 0.92 rad/s

3 0

3 years ago

A small glass ball rubbed with silk gains a charge of +2.0 uc. the glass ball is placed 12 cm from a small charged rubber ball t

Gre4nikov [31]

The magnitude of the electric force between two obejcts with charge $q_1$ and $q_2$ is given by Coulomb's law:
$F= k_e \frac{q_1 q_2}{r^2}$
where
$k_e = 8.99 \cdot 10^9 N m^2 C^{-2}$ is the Coulomb's constant
and r is the distance between the two objects.

In our problem, the distance is $r=12 cm=0.12 m$ , while the magnitudes of the two charges are
$q_1 = 2.0 \mu C=2.0 \cdot 10^{-6}C$
$q_2 = 3.5 \mu C = 3.5 \cdot 10^{-6} C$
(we can neglect the sign of the second charge, since we are interested only in the magnitude of the force).

So, using the formula and the data of the problem, we find
$F=(8.99 \cdot 10^9 N m^2 C^{-2} ) \frac{(2.0 \cdot 10^{-6} C)(3.5 \cdot 10^{-6} C)}{(0.12 m)^2}=4.37 N$

4 0

3 years ago