Answer: 0.8
Explanation:
The efficiency is defined as the ratio of total imput energy that is actually utilized to the end of the device.
So if we have a total transfer of 1500j of energy, and 1200j are used to heat the thing inside the kettle, 300j are not used to the actual function of the kettle.
So the efficiency is n = 1200j/1500j = 0.8
This means that a 80% of the energy imput is actually used to heat the kettle.
When water freezes, it's volume INcreases, which naturally results in a DEcrease in it's density. That's why cubes and bergs float.
I'm pretty sure that water is the only known substance that behaves this way. Which is lucky for us, because if it didn't, then life on Earth would be impossible. Oceans and lakes would freeze from the bottom up. Once! And then they would never thaw, because the sun could never cut through the layer of warm water on top, to melt the ice below.
Answer:
2.7ohms
Explanation:
Given parameters:
Voltage of the battery = 12V
Current = 4.5A
Unknown:
Resistance of the resistor = ?
Solution:
From Ohm's law, we know that;
V = IR
V is the voltage
I is the current
R is the resistance
So;
R = = = 2.7ohms
Answer:
The current would stop
Explanation:
Electric currents are interesting because they carry little to no momentum. As soon as you remove a power source, the whole current halts.
Summers are hot and winters are cold