Answer:
4 hrs
Explanation:
625 = 5000 (1/2)^n
625/5000 = 1/2^n
n = 3 half lives
3 half lives = 12 hours 1 half life = 4 hrs
Answer:
Explanation:
A mechanical wave is a wave that is an oscillation of matter, and therefore transfers energy through a medium. ... Therefore, the oscillating material does not move far from its initial equilibrium position. Mechanical waves transport energy. This energy propagates in the same direction as the wave.
The velocity of the wave on the string is given by

Solving the above equation,

The frequency of the wave
and wave length is 
The velocity is 
Substituting numerical values,

The length of the string is 
Answer:



Explanation:
As we know that all the batteries are in series
so the net voltage of all three batteries is given as

now we know that


now plug in all the values in it



now we have


<h2>
Answer: True </h2><h2>
</h2>
Each atom emits or absors electromagnetic radiation, but only in some frequencies that are characteristic of its chemical element.
Now, if we supply energy in the form of heat (thermal energy) to a certain element in its gas phase, this will be stimulated and its atoms will emit radiation in certain frequencies of the visible spectrum, which constitute its <u>emission spectrum</u>.
If the same element, also in gaseous state, receives electromagnetic radiation, it absorbs in certain frequencies of the visible spectrum, <u>precisely the same ones in which it emits when it is stimulated by heat</u>. This will be its <u>absorption spectrum.</u>
<h2>
This means that every element absorbs radiation in the same wavelengths in which it emits it. </h2>