14. It takes an airplane nearly ¾ of a mile to stop. Which law of motion is being used?

Problem 1: Spherical mirrorConsider a spherical mirror of radius 2 m, and rays which go parallel to the optic axis. What is thep

SIZIF [17.4K]

Answer:

1) iii i= 1m, 2) iii and iv, 3) i = f₂ (L-f₁) / (L - (f₁ + f₂))

Explanation:

Problem 1

For this problem we use two equations the equations of the focal distance in mirrors

f = r / 2

f = 2/2

f = 1 m

The builder's equation

1 / f = 1 / o + 1 / i

Where f is the focal length, "o and i" are the distance to the object and the image respectively.

For a ray to arrive parallel to the surface it must come from infinity, whereby o = ∞ and 1 / o = 0

1 / f = 0 + 1 / i

i = f

i = 1 m

The image is formed at the focal point

The correct answer is iii

Problem 2

For this problem we have two possibilities the lens is convergent or divergent, in both cases the back face (R₂) must be flat

Case 1 Flat lens - convex (convergent)

R₂ = infinity

R₁ > 0

Cas2 Flat-concave (divergent) lens

R₂ = infinity

R₁ <0

Why the correct answers are iii and iv

Problem 3

For a thick lens the rays parallel to the first surface fall in their focal length (f₁), this is the exit point for the second surface whereby the distance to the object is o = L –f₁, let's apply the constructor equation to this second surface

1 / f₂ = 1 / (L-f₁) + 1 / i

1 / i = 1 / f₂ - 1 / (L-f₁)

1 / i = (L-f₁-f₂) / f₂ (L-f₁)

i = f₂ (L-f₁) / (L - (f₁ + f₂))

This is the image of the rays that enter parallel to the first surface

6 0

4 years ago

A piece of silicon sample has a resistivity of 0.1 ω.Cm. Its thickness is 100µm. The electron mobility is 1350cm 2 v -1sec-1. Wh

lawyer [7]

The answer is Rh = 135 cm^3 and B = 0.05185 wh/m^2

Explanation:

Resitivity of silicon = 0.1

thickness = 100um

so, I = ma

Required to find out concentration of electron , we know that

Rh = up

By putting in the values,

Rh = 1350 x 0.1

Rh = 135 cm^3

Now consider,

Rh = 1 / Rh.q

= 1 / Rh . q

= 1 / 135 x1.609 x10^-19

= 4.6037 x 10^16 / cm^3

Vh = BIRh / w

B = Vh w/ IRh

B = -70 x10^-6 x 100 x10^-6 / 1x 10^-3 x 135 x 10^-6

B = 0.05185 wh / m^2

5 0

3 years ago

Manufactured bolts can’t be too long or too short or they might not fit where they need to. Help determine which bolts will work

Sever21 [200]

What is the longest the bolt can be and still be acceptable

5 0

3 years ago

You and your friends find a rope that hangs down 19m from a high tree branch right at the edge of a river. You find that you can

tangare [24]

Answer:

Explanation:

Given

length of rope $L=19\ m$

velocity while running $v=2\ m/s$

when the person jumps off the bank and hang on the rope then we can treat the person as pendulum with Time period T which is given by

$T=2\pi \sqrt{\frac{L}{g}}$

$T=2\pi \sqrt{\frac{19}{9.8}}$

$T=2\pi \times 1.392$

$T=8.74\ m/s$

Greatest Possible distance will be covered when person reaches the other extreme end of assumed pendulum (velocity=zero)

therefore he must hang on for 0.5 T time

$time=0.5\times 8.74=4.37\ s$

5 0

3 years ago

Please answer all of them <br>I'll give brainly if answer for points will be reported

enyata [817]

Answer:

Level 1-

1. It depends of the sense and the magnitude of the force

2. Electric force

3. A contact force need to touch to act in the object, like push a box for example. A non-contact force don't need to touch to act in the object, like an magnet attracting other magnet

4. The pressure is the force divided by the area. The unit for pressure in the international system is Pascal

5. Because the pressure is applied in all the surface of our bodies, so the force is divided by the surface area of our bodies.

Level 2-

1. The balloons stick to the walls because when she rubbed they in her clothes they earned eletric charge, and when they touched the wall, the electric charges of the wall got polarized and it creats a attraction force.

The same happened with the water stream. The balloons were charged with electric charges and the water was attracted by it.

2. Mass is the amount of matter, it's an scalar quantity. Weight is the force created by the attraction of a massive body as the Earth, and another body as a human, and a force is a vector

3. It's for increase the surface area, so the pressure will be decreased

4. When a person pulls up the syringe plunger the pressure inside the syringe is smaller than the pressure outside, so the pressure push the liquid into the syringe

5. a) The stream of the top is falling closer than the stream from the bottom, causa in the top the pressure is lower than in the bottom. In the bottom, beyond the air pressure, it has also the whole column of water making more pressure, so it goes far.

b) The streams are all near because the holes are in the same height, so the pressure is divided for all the holes.

Level 3-

1. The girl.

pressure of the girl: 50/1 = 50

pressure of the man: 100/25 = 4

pressure of the elephant: 4500/250 = 18

So, the girl exerts more pressure.

2. When the can is heated the air inside expands and get out of it. If you seal the mouth of the can, the air cannot return to inside it, and when it get colder the air inside will shrink back to the normal volume, so it will occupy less space and the outside pressure will exerts a force and deform the can.

4 0

3 years ago