A goldfish is capable of seeing which electromagnetic wave?

A dentist uses a concave mirror (focal length 2.5 cm) to examine some teeth. If the distance from the object to the mirror is 1.

AysviL [449]

Answer:

2.28

Explanation:

From mirror formula,

1/f = 1/u+1/v .......... Equation 1

Where f = focal length of the mirror, v = image distance, u = object distance.

Note: The focal length mirror is positive.

make v the subject of the equation,

v = fu/(u-f)............ Equation 2

Given: f = 2.5 cm, u = 1.4 cm

Substitute into equation 2

v = 2.5(1.4)/(1.4-2.5)

v = 3.5/-1.1

v = -3.2 cm.

Note: v is negative because it is a virtual image.

But,

Magnification = image distance/object distance

M = v/u

Where M = magnification.

Given: v = 3.2 cm, u = 1.4 cm

M = 3.2/1.4

M = 2.28.

Thus the magnification of the tooth = 2.28.

3 0

3 years ago

Your friend is wearing a red coat. When white light hits the coat, some light is reflected, and some is absorbed.

Vilka [71]

Answer:

Orange , yellow, green and blue

red coat absorbs all colors of visible light except red, so red light

is the only light left to bounce off of the coat toward our eyes.

4 0

2 years ago

Please help with these questions. All questions are in the image.

S_A_V [24]

1) Average speed

2) Displacement

Explanation:

1)

Speed is a scalar quantity which gives a measure of how fast a body is moving. It is equal to the ratio between the distance travelled by an object and the time taken to cover that distance:

$speed = \frac{d}{\Delta t}$

where

d is the distance covered

$\Delta t$ is the time taken

It is important to note that being a scalar, speed does not have any direction. Moreover, distance is also a scalar quantity, which corresponds to the total length of the path covered by the object, regardless on the direction taken.

So, the equation "travelled distance/elapsed time" corresponds to the average speed. (where the term average refers to the fact we are not measuring the speed at a specific instant in time, but on a certain time interval $\Delta t$ .

2)

Velocity is a vector quantity, so it has both a magnitude and a direction.

The magnitude of the velocity is given by:

$velocity=\frac{\Delta x}{\Delta t}$

where

$\Delta x$ is the change in position (or displacement) of the object

$\Delta t$ is the time taken

And the direction of the velocity corresponds to the direction of the displacement.

We must note that while distance does not depend on the direction, displacement does. In fact, displacement measures the difference between the initial and final position of the object.

Therefore, the equation "change in position / elapsed time" is equal to the average velocity.

Learn more about speed and velocity:

brainly.com/question/8893949 (speed)

brainly.com/question/5063905 (speed vs velocity)

brainly.com/question/5248528 (velocity)

#LearnwithBrainly

4 0

3 years ago

A cylinder is fitted with a piston, beneath which is a spring, as in the drawing. The cylinder is open to the air at the top. Fr

astraxan [27]

Answer:

x = 0.0734 m = 7.34 cm

Explanation:

First we shall calculate the area of the piston:

$Area = \pi radius^2\\Area = \pi (0.028\ m)^2\\Area = 0.00246\ m^2$

Now, we will calculate the force on the piston due to atmospheric pressure:

$Atmospheric\ Pressure = \frac{Force}{Area}\\\\Force = (Atmospheric\ Pressure)(Area)\\Force = (101325\ N/m^2)(0.00246\ m^2) \\Force = F = 249.56\ N$

Now, for the compression of the spring we will use Hooke's Law as follows:

$F = kx\\$

where,

k = spring constant = 3400 N/m

x = compression = ?

Therefore,

8 0

3 years ago

What is the total number of pounds of carbon dioxide that 2 trees remove from the air each<br> year?

Vikentia [17]

Answer:

On average, one acre of new forest can sequester about 2.5 tons of carbon annually. Young trees absorb CO2 at a rate of 13 pounds per tree each year. Trees reach their most productive stage of carbon storage at about 10 years at which point they are estimated to absorb 48 pounds of CO2 per year.

5 0

3 years ago

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