All categories

2 years ago

What is light intensity?

2 answers:

7 0

Light intensity is the "amount of light given off a light source." Also, is the measure the wavelength of the amount of light given off by a light source.

Hope this helps.

Vika [28.1K]2 years ago

4 0

It's the brightness of something, and is measured as the rate at which light energy is delivered to a unit of surface, or energy per unit time per unit area.

You might be interested in

How can eclipsing binary stars be identified?

Leviafan [203]

D) they become dimmer at regular intervals.

3 0

2 years ago

The earth has a net electric charge that causes a field at points near its surface equal to 150 N/C and directed in toward the c

maria [59]

To solve this problem we will start using the concepts related to the electric field, from there we will find the load exerted on the body. Through this load it will be possible to make a sum of forces in balance to find the load that a human supports. Finally with these values it will be possible to find the repulsive force. We will proceed as follows,

The electric field is

$E= \frac{kQ}{R^2}$

Here,

k = Coulomb's Constant

Q = Charge

R = Distance (At this case from the center of mass of the earth to the surface)

Rearranging to find the charge,

$Q = \frac{ER^2}{k}$

Replacing,

$Q = frac{(150)(6.38*10^6)}{8.99*10^9}$

$Q = 6.79*10^5 C$

Since the electric field is directed towards the center of earth, the charge is negative.

PART A) Once the load is found we can proceed to apply the balance of Forces, for which the electrostatic force must be equivalent to the weight, this in order to satisfy the balance, therefore

$F_w = F_e$

$mg = \frac{kQq}{R^2}$

Replacing,

$(62)(9.8) = \frac{(8.99*10^9)(q)(-6.79*10^5)}{(6.38*10^6)^2}$

Solving for q,

$q = -4.056C$

PART B) Finally using the given distance and the values of the found load we can find the repulsive Force, which is

$F =\frac{kq^2}{d^2}$

$F = \frac{(8.99*10^9)(-4.056)^2}{110^2}$

$F = 1.22*10^7N$

PART C) The answer is no. According to the information found, we can conclude that traveling through an electric field is not viable because there is a repulsive force of great magnitude acting on the body.

3 0

2 years ago

the mass of a brick is 4 kg, find the mass of water displaced by it when completely immersed in water.

vova2212 [387]

Answer:

The correct answer is = 1.6

Explanation:

Density of water = 1000kg/m³ = d₁

Mass of brick = 4kg = m

Density of brick = 2.5 g/cm³ = 2.5 × 1000 =2500 kg/m³ = d₂

Volume of brick = m/d₂ = 4/2500 =16/10000 = 0.0016 L = v

Buoyant Force = v × d₁ × g (g= acceleration due to gravity =9.8m/s²)

= 0.0016 × 1000 × 9.8 = 15.68 Newtons

By the Archimedes' Principle, the buoyant force is equal to the weight of the liquid displaced by an object.

Weight of the water displaced=Buoyant Force

=Mass of water displaced × g,

as weight = mass × acceleration due to gravity

15.68= mass of brick × 9.8

15.68/9.8 =Mass of water displaced

1.6 kg = Mass of water displaced

4 0

2 years ago

A player kicks a football from ground level with a velocity of 26.2m/s at an angle of 34.2° above the horizontal. How far back f

Amanda [17]

For the ball to go straight into the goal, the kicker needs to be no more than 6.54 meters away from the goal.

For the ball to arc into the goal, the kicker needs to be between 58.5 and 65.1 meters away from the goal.

<h3>Explanation</h3>

How long does it take for the ball to reach the goal?

Let the distance between the kicker and the goal be $x$ meters.

Horizontal velocity of the ball will always be $26.2\times\cos{34.2\textdegree}$ until it lands if there's no air resistance.

The ball will arrive at the goal in $\displaystyle \frac{x}{26.2\times\cos{34.2\textdegree}}$ seconds after it leaves the kicker.

What will be the height of the ball when it reaches the goal?

Consider the equation

$\displaystyle h(t) = -\frac{1}{2}\cdot g\cdot t^{2} + v_{0,\;\text{vertical}} \cdot t + h_0$ .

For this soccer ball:

$g = 9.81\;\text{m}\cdot\text{s}^{-2}$ ,
$v_{0,\;\text{vertical}} = 26.2\times \sin{34.2\textdegree{}}\;\text{m}\cdot\text{s}^{-2}$ ,
$h_0 = 0$ since the player kicks the ball "from ground level."

$\displaystyle t=\frac{x}{26.2\times\cos{34.2\textdegree}}$

when the ball reaches the goal.

$\displaystyle h= - 9.81 \times \frac{x^2}{(26.2\times\cos{34.2\textdegree})^2} + (26.2 \times \sin{34.2\textdegree})\times\frac{x}{26.2\times\cos{34.2\textdegree}} \\\phantom{h} = -\frac{9.81}{(26.2\times\cos{34.2\textdegree})^2}\cdot x^{2} + \frac{\sin{34.2\textdegree}}{\cos{34.2\textdegree}}\cdot x$ .

Solve this quadratic equation for $x$ , $x > 0$ .

$x = 65.1$ meters when $h = 0$ meters.
$x = 6.54$ or $58.5$ meters when $h = 4$ meters.

In other words,

For the ball to go straight into the goal, the kicker needs to be no more than 6.54 meters away from the goal.
For the ball to arc into the goal, the kicker needs to be between 58.5 and 65.1 meters away from the goal.

3 0

2 years ago

A truck moving at 7.0 meters per second accelerates to a speed of 15.0 meters per second within a time of 1.5 seconds. Calculate

Alborosie

Answer:

I WANT TO BE HANDSOME AND I WANT TO BE HEARTTHROB!

SO GIRLS PLEASE LOVE ME!

Explanation:

I WANT TO BE HANDSOME AND I WANT TO BE HEARTTHROB!

SO GIRLS PLEASE LOVE ME!

3 0

2 years ago

What is light intensity? ​

What is light intensity?