For each picture below identify the material and closing the sandwich as transparent translucent or opaque

WA

brilliants [131]

Answer:

the answers the correct one is d

Explanation:

The speed of sound is constant so we can use the relations of uniform motion

v = x / t

x = v t

now let's calculate the distance for each person

t = 5s

x₁ = 300 5

x₁ = 1500 m

t = 6s

x₂ = 300 6

x₂ = 1800 m

therefore we have two possibilities

a) the two people are on the same side, therefore the distance between them is

Δx = x₂- x₁

Δx = 1800 - 1500

Δx = 300 m

let's reduce to km

Δx = 0.300 km

b) people are on opposite sides of the sound

Δx = x₂ + x₁

Δx = 1800 + 1500

Δx = 3300 m

Δx = 3.3 km

when checking the answers the correct one is d

3 0

3 years ago

A stone is launched from the ground, at a 70° angle, with an initial velocity of 120 m/s.

zavuch27 [327]

<span>A) x = 41t
The classic equation for distance is velocity multiplied by time. And unfortunately, all of your available options have the form of that equation. In fact, the only difference between any of the equations is what looks to be velocity. And in order to solve the problem initially, you need to divide the velocity vector into a vertical velocity vector and a horizontal velocity vector. And the horizontal velocity vector is simply the cosine of the angle multiplied by the total velocity. So H = 120*cos(70) = 120*0.34202 = 41.04242 So the horizontal velocity is about 41 m/s. Looking at the available options, only "A" even comes close.</span>

3 0

3 years ago

Read 2 more answers

An inductor in an LC circuit has a maximum current of 2.4 A and a maximum energy of 56 mJ.

Harrizon [31]

Answer:

The energy stored in the capacitor, when the current in the inductor is 1.2 A, is 41.6 mJ.

Explanation:

In a LC oscillating circuit, the energy is stored in the electric field (between the plates of the capacitor) and in the magnetic field (surrounding the wires of the inductor).

At any time, the sum of both energies can be expressed as follows:

E = 1/2 Q² / C + 1/2 L I²

In this type of circuit, energy oscillates, which means that it is exchanging between both fields all time.

When the capacitor is completely discharged, all the energy is stored in the magnetic field, and at that time, the current is maximum.

The total energy, when I is maximum, can be written as follows:

E = 1/2 L I² (1)

In our case, when I= 2.4A, E= 56 mJ.

So, we can find out the value of L, which will allow us to know the value of the magnetic energy at any time, having the value of the instantaneous current.

Solving for L in (1):

L = 2 *.56 mJ / (2.4)² A² = 20 mH

The next step is getting the value of the energy stored in the inductor, when I = 1.2 A, as follows:

Em = 1/2 *20 mH.* (1.2)² A² = 14.4 mJ

As the total energy must be always the same, i.e., 56 mJ, the energy stored in the capacitor, assuming no losses, must be the difference between the total energy and the one stored in the magnetic field:

Ec = 56 mJ - 14.4 mJ = 41.6 mJ

3 0

3 years ago

Which equation is correct according to Ohm’s law? Which equation is correct according to Ohm’s law? A.) V = IR B.) I = R/V C.) R

vodomira [7]

Answer:

$V = IR$