Question

the position vector for an electron is r = 5.0m i-3.0m j 2.0m k find magnitude of r

Answer 1

Answer:

Easy.

Explanation:

Before getting started with the experiment, it is important to understand a few terms that are used in a concave mirror and convex lens:

Centre of curvature: For a curved mirror, the centre of curvature, C can be defined as the centre of a hollow glass sphere of which a curved mirror is a part.

Radius of curvature: For a curved mirror, the radius of curvature, R can be defined as the radius of the hollow glass sphere of a spherical mirror is part.

Principal axis: Principal axis is defined as the imaginary line passing through the pole and centre of curvature of the spherical mirror.

Principal focus: Principal focus is defined as a point at which the reflected rays meet or appear to meet for the spherical mirror. For a concave mirror, the principal focus is in the front and for a convex mirror, the principal focus is at the behind.

Below is an experiment to determine the focal length of a concave mirror and convex lens.

Aim

To determine the focal length of:

Concave mirror

Convex lens by obtaining the image of a distant object.

Theory

How to find focal length of concave mirror?

Following are the ways to obtain the focal length of the concave mirror:

A concave mirror is defined as the spherical mirror whose reflecting surface is curved inwards and follows laws of reflection of light.

The light rays coming from a distant object can be considered to be parallel to each other.

If the image formed is real, inverted and very small in size, then the parallel rays of light meet the point in the front of the mirror.

The image formed by the convex lens is real and can be obtained on the screen.

f is used to denote the difference between the principal axis P and the focus F of the concave mirror.

How to find the focal length of convex lens?

Following are the ways to obtain the focal length of convex lens:

The convex lens is thicker in the middle and thinner at the edges and is also known as the converging lens.

The refracted rays from the parallel beam of light converge on the other side of the convex lens.

If the image is obtained at the focus of the lens, the image would be real, inverted and very small.

f is the focal length which is the difference between the optical centre of the lens and the principal focus.

The image can be obtained on the screen as the image formed by the lens is real.

To determine focal length of a given concave mirror

Materials Required

A concave mirror

A measuring scale

A screen holder

A mirror holder

A mirror stand

Answer 2

Answer:

The position of an electron is given in vector form as, r = 5.0m i-3.0m j 2.0m k, the magnitude of position is  $\sqrt{38}m$

Explanation:

• A vector is a physical quantity that has both magnitude and direction to represent it

• The position vector is a kind of vector that gives the position of an object

• The magnitude of a vector in component form, that is $A=ai+bj+ck$ is given by the formula

        $/A/=\sqrt{a^{2} +b^{2} +c^{2} }$

From the question,

the position of an electron $r=5i-3j+2k$

the components are

$a=5\\b=-3\\c=2$

by putting the values, we get

$/r/=\sqrt{5^{2} +3^{2} +2^{2} } =\sqrt{38}m$