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3 years ago

Describe how compass needle move when it is placed in a magnet ?

Physics

1 answer:

bagirrra123 [75]3 years ago

3 0

Answer:

The compass needle will point towards the magnetic field, so if it is in a magnet it will most likely spin around in circles.

Explanation:

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Suppose you have two identical sheets of paper and you crumple one of the sheets of paper into a ball. If you drop the crumpled

sammy [17]

Answer:

Because it can easily resist air resistance.

Explanation:

Since air resistance is not negligible, the crumpled paper will reach the ground first because it can easily resist air resistance surrounding it compare to the un-crumpled one that will be influenced by the air thereby causing the un-crumpled paper to spend more time in the air

3 0

3 years ago

The focal length for a spherical convex mirror is –20 cm. What is its radius of curvature?

Svetradugi [14.3K]

Answer:

40 cm

Explanation:

The focus of a spherical convex mirror is the point at which the rays of an object converge in the infinite, it is also the point at which an object must be placed so that its image is formed in the infinite. The distance from the focus to the origin is called the focal length and is called f. It is related to the radius of the mirror, R, according to:

$f=-\frac{R}{2}$

rewriting for R:

$R=-2f=-2*-20cm=40 cm$ .

4 0

3 years ago

Calculate the change in the energy of an electron that moves from the n = 3 level to the n = 2 level. What type of light is emit

marissa [1.9K]

Answer:

Red light

Explanation:

The energy emitted during an electron transition in an atom of hydrogen is given by

$E=E_0 (\frac{1}{n_2^2}-\frac{1}{n_1^2})$

where

$E_0 = 13.6 eV$ is the energy of the lowest level

n1 and n2 are the numbers corresponding to the two levels

Here we have

n1 = 3

n2 = 2

So the energy of the emitted photon is

$E=(13.6) (\frac{1}{2^2}-\frac{1}{3^2})=1.9 eV$

Converting into Joules,

$E=(1.9 eV)(1.6\cdot 10^{-19} J/eV)=3.0\cdot 10^{-19} J$

And now we can find the wavelength of the emitted photon by using the equation

$E=\frac{hc}{\lambda}$

where h is the Planck constant and c is the speed of light. Solving for $\lambda$ ,

$\lambda=\frac{hc}{E}=\frac{(6.63\cdot 10^{-34})(3\cdot 10^8)}{3.0\cdot 10^{-19}}=6.63\cdot 10^{-7} m = 663 nm$

And this wavelength corresponds to red light.

5 0

3 years ago

which of the folloing statements about ionization energy is true? A elements toward the bottom of a group periodic table general

beks73 [17]

accept the flow of electrons.resist the flow of electrons.accept the flow of protons.resist the flow of protons.It is one of these

6 0

3 years ago

Identify which one is chemical change, chemical property,physical change and physical property

Ulleksa [173]

Answer:

Heat conductivity: Physical property

Silver tarnishing: chemical change

Sublimation: physical change

Magnetizing steel: physical property

Length of a metal object: physical property

Shortening melting: physical property

exploding dynamite: chemical change

combustible: chemical property

water freezing: physical change

Acid resistance: chemical property

brittleness: physical property

milk souring: chemical change

baking bread: chemical change

Explanation:

First you need to understand the differences between physical and chemical change; physical and chemical property.

Physical properties vs chemical properties:

Physical properties are properties that you can observe without changing the substance's composition. This means you can measure these properties without changing them chemically.

Chemical properties, on the other hand, are properties are not as direct. These properties are generally determined by the way the react with other substances changing their composition.

Physical changes vs chemical changes:

A substance that undergoes physical change does not change in chemical composition. They may look physically different in terms of size and shape, but overall, their chemical composition remains constant. The best example would be water. Water can change phases, from solid to liquid when they melt. Essentially, they look like different substances, but the change is only physical and not chemical.

Chemical change, is different by the fact that they change in chemical composition. Bonds are broken and/or made through the reaction, which changes them not only physically but chemically as well. Some of the most indicative signs of a chemical change occurring are: change in color, odor, production of gas, production of light/heat.

4 0

3 years ago