We simply use the formula,
Given, velocity = 4 m per s and distance = 120 m.
Substituting these values, we get
.
Thus, required time for the elevator in order to travel 120 m upwards is 30 s.
Explanation:
The lines in the spectra of star is due to absorption of light emitted by star by different elements present in atmosphere of the star .
If some element is present in the outer atmosphere of he star , it will absorb a particular portion of light , for which there will be black line in the spectrum .
These are called Fraunhoffer's lines .
Now there is no such line at the place of Helium in the light spectrum . This means that Helium element is not present in the outer atmosphere of the star.
Iron atoms are heavier than gold atoms
Explanation:
Chart:
Materials Specific heat
Gold 0.129
Iron 0.45
The specific heat of a substance is the amount of heat required to raise the temperature of 1g of the substance by 1K.
We can see that the more the mass of a substance, the higher the specific heat needed to raise the temperature.
Specific heat is directly proportional to the mass of substance.
It also dependent on the amount of heat supplied and the nature of the substance.
- The mass of a body is the amount of substance it contains.
- A heavier substance has more number of atoms in it.
- Since iron has a higher specific it, the atoms must be heavier or more than that of gold.
learn more:
Specific heat brainly.com/question/7210400
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For the answer to the question above, let us first start with relaxation time. it is the absence of an external electric field, the free electrons in a metallic substance will move in random directions so that the resultant velocity of free electrons in any direction is equal to zero. While the Collision time it is<span> the mean </span>time<span> required for the direction of motion of an individual type particle to deviate through approximately as a consequence of </span>collisions<span> with particles of type.</span>
