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3 years ago

Are glasses lenses concave or convex?

Physics

1 answer:

Olegator [25]3 years ago

8 0

Answer:

Eyeglass lenses will almost always be convex on the outer surface, the one farthest from the eye, simply to fit it to the curvature of the face.

Explanation:

Hope this helped Mark BRAINLIEST!!!

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Electric energy is generated at a nuclear power plant using which type of nuclear reaction

aalyn [17]

Instead, they use uranium fuel, consisting of solid ceramic pellets, to produceelectricity through a process called fission. Nuclear power plants obtain the heat needed to produce steam through a physical process. This process, called fission, entails the splitting of atoms of uranium in a nuclear reactor.

6 0

4 years ago

Read 2 more answers

Diagnostic ultrasound of frequency 3.82 MHz is used to examine tumors in soft tissue. (a) What is the wavelength in air of such

maxonik [38]

Explanation:

It is given that,

Frequency of diagnostic ultrasound, f = 3.82 MHz = 3820 Hz

The speed of the sound in air, v = 343 m/s

(a) We need to find the wavelength in air of such a sound wave. Let it is given by λ₁

i.e. $\lambda=\dfrac{v}{\nu}$

$\lambda_1=\dfrac{343\ m/s}{3820\ Hz}$

$\lambda_1=0.089\ m$

(b) If the speed of sound in tissue is 1650 m/s .

$\lambda_2=\dfrac{v}{\nu}$

$\lambda_2=\dfrac{1650\ m/s}{3820\ Hz}$

$\lambda_2=0.43\ m$

Hence, this is the required solution.

7 0

3 years ago

Equation: S=D]

Ahat [919]

The speed of car is 106.67 miles per hour

To solve problems involving speed and distance we are required to first find speed or distance travelled in an hourly timeframe

It is given that car takes 4 hours to cover the distance at a speed of 40 miles per hour

Therefore, total distance travelled by the car= speed x time

= 40 miles per hour x 4 hour

=160 miles

We are required to find the speed of the car if the distance is to be covered in 1.5 hours

We are required to find the speed by the formula speed= Distance/time

distance= 160 miles time = 1.5 hour

speed= 160/1.5=106.666=106.67 miles per hour

Hence the speed is 106.67 miles per hour

For further reference:

brainly.com/question/10930186?referrer=searchResults

#SPJ9

7 0

2 years ago

Is the refraction different entering medium that has a higher index of refraction compared to entering amedium that has a lower

oee [108]

Answer:

Yes

Explanation:

The speed of light when it travels through glass, diamond, etc, the light travels at different speed from the speed of light. Speed of the light in material is related to the index of refraction.

The change in speed which occurs when the light passes from one medium to the another is responsible for bending of the light which is called as refraction.

When the light goes into a medium with the higher index of the refraction, light bends towards normal. Conversely, if the light traveling goes from higher refractive index to lower refractive index, it will bend away from the normal.

Hence, the refraction is different in both the scenario.

6 0

3 years ago

c) If the ice block (no penguins) is pressed down even with the surface and then released, it will bounce up and down, until fri

eduard

Answer:

y = 20.99 V / A

there is no friction y = 20.99 h

Explanation:

Let's solve this exercise in parts: first find the thrust on the block when it is submerged and then use the conservation of energy

when the block of ice is submerged it is subjected to two forces its weight hydrostatic thrust

F_net= ∑F = B-W

the expression stop pushing is

B = ρ_water g V_ice

where rho_water is the density of pure water that we take as 1 10³ kg / m³ and V is the volume d of the submerged ice

We can write the weight of the body as a function of its density rho_hielo = 0.913 10³ kg / m³

W = ρ-ice g V

F_net = (ρ_water - ρ_ ice) g V

this is the net force directed upwards, we can find the potential energy with the expression

F = -dU / dy

ΔU = - ∫ F dy

ΔU = - (ρ_water - ρ_ ice) g ∫ (A dy) dy

ΔU = - (ρ_water - ρ_ ice) g A y² / 2

we evaluate between the limits y = 0, U = 0, that is, the potential energy is zero at the surface

U_ice = (ρ_water - ρ_ ice) g A y² / 2

now we can use the conservation of mechanical energy

starting point. Ice depth point

Em₀ = U_ice = (ρ_water - ρ_ ice) g A y² / 2

final point. Highest point of the block

$Em_{f}$ = U = m g y

as there is no friction, energy is conserved

Em₀ = Em_{f}

(ρ_water - ρ_ ice) g A y² / 2 = mg y

let's write the weight of the block as a function of its density

ρ_ice = m / V

m = ρ_ice V

we substitute

(ρ_water - ρ_ ice) g A y² / 2 = ρ_ice V g y

y = ρ_ice / (ρ_water - ρ_ ice) 2 V / A

let's substitute the values

y = 0.913 / (1 - 0.913) 2 V / A

y = 20.99 V / A

This is the height that the lower part of the block rises in the air, we see that it depends on the relationship between volume and area, which gives great influence if there is friction, as in this case it is indicated that there is no friction

V / A = h

where h is the height of the block

y = 20.99 h

7 0

4 years ago