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:
Store chemical energy and transfer it to electrical energy when a circuit is connected.
Explanation:
A battery (single cell) is a container made of one cell that can produce a particular amount of electrical energy when needed.
It works by converting chemical energy to electric energy which is then used as a power source.
It stores up chemical energy and when connected to an external circuit, it provides electrical energy (through the flow of electrical current) to the circuit.
A battery is usually made up of a positive electrode and a negative electrode.
Answer:
Both technicians are right.
Explanation:
Torque is defined as a rotational force that can be calculated by the formula T= F.d. Being F the force applied to a body to make it rotate and d the distance since the force is applied.

So technician A is saying that gear can apply a torque to another gear, and that is true because it’s applying a rotational force to the gear next to it, in simple terms -anytime I make something rotate, I'm generating a torque-. And for technician B, the torque also can vary as a function of the distance of the force applied (size of the gear), so, it can multiply the torque and change the rotation speed.
A is only the area of one tile. It wants the area of the whole floor.
area of parallelogram is b*h=0.952. There are 9500 of them so 0.952*9500=904.4 (answer c)