。and 。 are needed to describe a force

A thin film of cryolite ( nc = 1.34 ) is applied to a camera lens ( ng = 1.58 ). The coating is designed to reflect wavelengths

rosijanka [135]

Answer:

=99.07nm

Explanation:

minimum thickness

2nd = (m - 1/2)λ

d = (m - 1/2)(λ/2n)

refractive index of the thin film, n = 1.34

minimum thickness m = 1

light wavelength λ = 531nm

d = (1 - 1/2) (531 / (2)(1.34)

d = 531/5.36

= 99.07nm

3 0

3 years ago

Which wave has a greater frequency?

DedPeter [7]

The wave diagramed in blue.

8 0

2 years ago

Read 2 more answers

4. Johnny exerts a 3.55 N rightward force on a 0.200-kg box to accelerate it across a low-friction track. If the total resistanc

Anon25 [30]

a) $15.2 m/s^2$

b) 1.96 N

c) 1.96 N

Explanation:

a)

To find the box's acceleration, we have to find first the net force acting on the box in the horizontal direction.

We have:

- The forward force of 3.55 N

- The backward, resistive force of 0.52 N

So, the net force forward is

$\sum F=3.55-0.52=3.03 N$

Now we can find the acceleration by using Newton's second law of motion, which states that:

$\sum F=ma$

where

m = 0.200 kg is the mass of the box

a is its acceleration

And solving for a, we find the acceleration:

$a=\frac{\sum F}{m}=\frac{3.03}{0.200}=15.2 m/s^2$

b)

The gravitational force on an object is the force with which the object is pulled towards the ground by the Earth.

It is given by

$W=mg$

where

m is the mass of the object

g is the gravitational field strength

In this problem we have

m = 0.200 kg is the mass of the box

$g=9.8 m/s^2$ is the gravitational field strength

So, the gravitational force on the box is

$W=(0.200)(9.8)=1.96 N$

c)

The normal force is the reaction force exerted by the floor on the box, in the upward direction.

In order to find the magnitude of this force, we apply Newton's second law of motion along the vertical direction.

We have two forces in this direction:

- The gravitational force, W, downward

- The normal force, N, upward

So the net force is

$\sum F=N-W$

According to Newton's second law,

$\sum F=ma$

However, the box is at rest in the vertical direction, so the vertical acceleration is zero:

$a=0$

This means that the net force is zero:

$\sum F=0$

And so, we can find the normal force:

$N-W=0\\N=W=1.96 N$

4 0

2 years ago

How do we get this equation ??<br><br><br> H=V^2÷R

lesantik [10]

$H=\frac{V^2}{R}\times t$ is the equation that represents the Joule's law of heating.

<h3>Explanation:</h3>

Joule's law of heating defines the heat generated by any current flowing conductor is directly proportional to

1. Square of Current (I²),

2. Resistance of the conductor (R)

3. Time for which current is passed (t)

Hence, Heat generated = $H = I^2 Rt$ .....................(1)

By Ohm's Law, the potential difference (V) across a conductor is directly proportional to the current(I) flowing through it. The constant of proportionality is termed as resistance of the conductor (R).

$V\ \alpha\ I\\V=I\times R$ ...............................................(2)

From (2), Current (I) can be rewritten as

$I = \frac{V}{R}$ ........................................................(3)

Substituting (3) in (1), we get

$H = I^2\times R\times t \\=(\frac{V}{R} )^2\times R\times t\\\\=\frac{V^2}{R^2}\times R\times t = \frac{V^2}{R}\times t\\\\ H =\frac{V^2}{R}\times t$

3 0

3 years ago

Có thể một lực hướng tâm tạo ra công trên một vật hay không? Hãy giải thích

Verdich [7]

Answer:

Explanation:

Công là sản phẩm của một lực và độ dời theo phương của lực đó. Vì lực hướng tâm luôn tác dụng vuông góc với chuyển động nên Không thể xảy ra công việc nào.

8 0

3 years ago