Answer:
She is not getting a good deal.
Explanation:
The equation that relates heat with mass, specific heat and temperature change of an object is 
.
Always convert temperature to Kelvin, although in our case it's not necessary because the 
will be the same, and we will leave the mass in grams because we will be getting 
units for specific heat, which we can compare to the one given for gold.
We then calculate the specific heat of the object in question:
Which shows it's not gold.
In a parallel circuit, the equivalent resistance is the reciprocal of (the sum of the individual reciprocals).
1/R = 1/10 + 1/21 + 1/13
1/R = 0.225 mhos
R = 4.45 ohms
I = V / R
The total current out of the battery is
I = (9v)/(4.45ohms)
I = 2.02 Amperes
As the total current leaves the battery, it splits into 3 paths, and each resistor gets part of it. The 10ohm resistor gets the most current; the 21ohm resistor gets the least current. After flowing through the resistors, the 3 currents join and add up to 2.02 Amperes again, and the same current returns to the battery.
Each resistor has the same 9v of EMF across it.
<span>An electromagnet works or turns into a magnet when an electric current passes through it, causing it to produce a magnetic field.<span> When they </span></span><span><span><span>alternating current is </span>passed through opposing
pairs of magnets, a rotating magnetic field is created, which "induces"
(creates) a magnetic field in the motor's rotor, causing it to spin.</span> </span>
Answer:
d) 
Explanation:
β₁ = sound level of sound at rock concert = 120 dB
β₂ = sound level of sound due to whisper = 21 dB
I₁ = Intensity of sound at rock concert
I₂ = Intensity of sound due to whisper
sound level of sound at rock concert is given as
Eq-1
sound level due to whisper is given as
Eq-2
subtracting Eq-2 from Eq-1
