In the diagram, the wavelength is shown by :

What element has 5 valence electrons and is in period 3.

Maru [420]

Answer:

Phosphorous

Explanation:

it is the fifth element from the left and it is in the third period so it has 5 valence electrons

5 0

3 years ago

An object of 4 cm length is placed at a distance of 18 cm in front of a convex mirror of radius of curvature 30 cm. Find the pos

erica [24]

Answer:

The position is 8.18cm from the mirror.

Nature is b=virtual

Size is 1.82cm

Explanation:

Note that for a convex mirror, the image distance and the focal length are negative;

Given

Object height H0 = 4cm

object distance u = 18cm

Radius of curvature R = 30cm

Since f = R/2

f = 30/2

f = -15cm

Recall that:

$\frac{1}{f} =\frac{1}{u}+ \frac{1}{v}\\\frac{1}{-15}=\frac{1}{18}+\frac{1}{v} \\\frac{1}{v} =\frac{1}{-15} -\frac{1}{18}\\ \frac{1}{v} = \frac{-18-15}{270}\\\frac{1}{v} = \frac{-33}{270}\\v=\frac{-270}{33}\\v=-8.18cm$

Since the image distance is negative, this shows that the image is a virtual image.

To get the size:

$\frac{H_1}{H_0}=\frac{v}{u}\\\frac{H_1}{4}=\frac{8.18}{18}\\18H_i=32.72\\H_i=\frac{32.72}{18}\\H_i= 1.82cm$

3 0

3 years ago

What is non uniform velocity

saul85 [17]

Answer:

"Non-uniform velocity" occurs when an object changes its velocity upon motion. This happens when the object either accelerates or decelerates (negative acceleration) in its speed or changes its direction.

Explanation:

"Velocity" refers to speed with a specific direction.

If the velocity is uniform, there's no change in speed and direction. However, if changes occur on either the speed, direction or both, then the velocity becomes variable or non-uniform.

For example, when it comes to a moving car, it is said to be in non-uniform velocity if the distances covered is unequal in relation to the equal intervals of time.

8 0

3 years ago

A light wave encounters a partial physical barrier, such as a wall with a hole in it. What is MOST LIKELY to occur?

tatiyna

Most likely, the light wave will be absorbed by the wall. Without any information as to the size and color of the wall, the location and size of the hole, or the location of the light wave, this is a generalized probability problem. For all of the places the light could be, it's more likely that it hits the wall than the hole (if the hole is less than 50% of the area of the wall).

5 0

3 years ago

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3. What is the gravitational force between a 70 kg physics student and her 1 kg textbook, at a distance of 1 meter? (This number

Rina8888 [55]

ANSWER