Answer:
B) 2.7W
Explanation:
Converting Cal to Joule
1 cal = 4.186J
14 kcal = 14 x 1000 x 4.186
= 58604 J
Converting hour to seconds
6 hours = 6 x 60 x 60 seconds
= 21600 seconds
Power is the time rate of doing work.
Power = Work/Time
P = (58604) / (21600)
P = 2.7W
Answer:
12 neutrons
Explanation:
The number of protons also shows the atomic number. Therefore the element in question is Krypton (Kr), which also is a noble gas.
Neutrons = Mass number - protons - electrons
Here neutrons = 84 - 36 - 36 = 12
Answer:
P = VI = (IR)I = I2R
Explanation:
What the equation means is that if you double the current you end up with 4 times the power loss. It's like the area of carpet you need for a room - if you make the room twice as long and twice as wide you need 4x as much carpet. The physical explanation is that the voltage difference along a wire depends on the current - more current flowing with a resistance means more voltage (pressure of electricity if you like) is built up.
This extra voltage means more power. So if you double the current your would double the power, but you also double the voltage which doubles the power again = 4x as much power. P = VI = (IR)I = I2R
I hope this helps you out, if I'm wrong, just tell me.
Answer:
-100N
Explanation:
Newton's third law of motion states that to every force exerted on one body, there is an equal and opposite force. This means that if object A exerts an ACTION force on B, there is a force called REACTION FORCE, which is equal and opposite, exerted on A by B.
The action and reaction forces are equal in size/magnitude but opposite in direction. In this case where a tennis racket strikes a tennis ball with a force (action force) of 100N, the ball will strike the racket with a reaction force of -100N.
F(RB) = -F(BR)
<span> The boiling point of water at sea level is 100 °C. At higher altitudes, the boiling point of water will be.....
a) higher, because the altitude is greater.
b) lower, because temperatures are lower.
c) the same, because water always boils at 100 °C.
d) higher, because there are fewer water molecules in the air.
==> e) lower, because the atmospheric pressure is lower.
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Water boils at a lower temperature on top of a mountain because there is less air pressure on the molecules.
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I hope this is helpful. </span>
