Sound level at distance of 15 m is given as 20 dB
so intensity at this distance is given as



now if we move closer to some some distance the sound level is now 50 dB
now the intensity is given as



now we know that



so now the distance from friend must be 47 cm
Answer:
In a circuit ,<u> VOLTAGE </u>can be said to be the "source" or the "push of electrons". This push then creates what is known as a <u> CURRENT , </u>which is the flow of electric charge through the circuit. This flow can the slowed down or restricted by <u>RESISTOR </u>, and this is also what can be harnessed in order to use electric <u>ENERGY </u>.
Explanation:
Voltage:
It is the 'push' that causes charges to move in a wire or other electrical conductor, also it is a Source input to the electric circuit.
Measured in Volts.
Current:
An electric current is the rate of flow of electric charge from a point or through a region.
Measured in Ampere.
Resistor:
Resistor is used to resist the flow of charge or to resist the current called as Resistance.
Measured in Ohms.
Electric Energy:
Electrical energy is a form of energy resulting from the flow of electric charge.
Measured in Joules.
In a circuit , voltage can be said to be the "source" or the "push of electrons". This push then creates what is known as a current, which is the flow of electric charge through the circuit. This flow can the slowed down or restricted by resistor, and this is also what can be harnessed in order to use electric energy.
The term you need to know is equilibrium. Technically it means that heat gained = heat lost. Normally in beginning chemistry classes the evidence for this condition is a stable temperature.
Women should eat 1,200 men should eat 1,800
Potential energy = mass x acceleration due to gravity x height
= 2.5 x 9.8 x 2.2
= 53.9 J.
Hope this helps!