The correct answer is letter D. candela. The unit for measuring the rate at which light energy is radiated from a source is the candela. L<span>umen is the unit for measuring the total amount of visible light emitted by a source. Lux is lumen per square meter. </span>
<u>Answer:</u>
<h2>
All the waves are pertubations that propagate (transport) energy.</h2><h2>
</h2>
Nevertheless, they have some differences:
1. Light waves are<u> electromagnetic waves</u>, while sound and water waves are <u>mechanical waves</u>, this is the first and principal difference.
2. Electromagnetic waves can<u> propagate in vacuum</u> (they do not need a medium or material), but mechanical waves obligatory need a material to propagate
3. Light waves are always <u>transversal waves</u>, this means <u>the oscillatory movement is in a direction that is perpendicular to the propagation</u>; but mechanical waves may be both: <u>longitudinal waves</u> (the oscillation occurs in the same direction as the propagation) or transversal waves.
4. Electromagnetic waves propagates at a <u>constant velocity</u> (Light velocity) while the velocity of mechanical waves will depend on the type of wave and the <u>density</u> of the medium or material.
5. <u>Mechanical waves</u> are characterized by the regular variation of a single magnitude, while <u>electromagnetic waves</u> are characterized by the variation of two magnitudes: the electric field and the magnetic field
6. <u>Water waves</u> are 2-dimensional waves, while the <u>light and the sound</u> are tridimensional spherical waves
7. Light waves <u>transports energy in the form of </u><u>radiation</u>, while mechanical waves t<u>ransport energy with </u><u>material</u>
As we know that the formula of kinetic energy will be
now here we know that
m = 2 kg
v = 1 m/s
so from the above equation we have
Answer:
Please find the answer in the explanation
Explanation:
Friction is a force that opposes motion. One or two of the advantages of friction are break and ability of an object to walk.
Writing yes it is useful because when your writing because friction helps you see what your writing
ii. Rubbing. Yes, it is useful.
friction make it possible for two object to rub each other
iii. Skiing. No. It is not useful because With presence of friction, skiing will not be possible.
iv. Rotating a wheel No. It is not useful because Friction will oppose the rotation of the wheel.
Answer: The earth is comprised of silicate materials as well as metals. The amount of gas is less here because of its location near to the sun. Due to its relative high surface temperature, the gases such as hydrogen and helium gets evaporated and disappears.
Whereas the sun is entirely comprised of hydrogen and helium gas, of which hydrogen is the dominant one. It has an extremely high temperature of about 5500°C.
