Answer:
2*10^-<em>5</em>
Explanation:
<em>B=</em><em>I</em><em>L</em>
<em>I=</em><em>B</em><em>/</em><em>L</em>
<em>I=</em><em>0</em><em>.</em><em>0</em><em>0</em><em>2</em><em>0</em><em>*</em><em>1</em><em>0</em><em>^</em><em>-</em><em>4</em><em>/</em><em>1</em><em>0</em>
<em>I=</em><em>2</em><em>*</em><em>1</em><em>0</em><em>^</em><em>5</em>
efficiency = (useful energy transferred ÷ energy supplied) × 100
It's easy to use this formula, but we have to know both the useful energy and the energy supplied. The drawing doesn't tell us the useful energy, so we have to find a clever way to figure it out. I see two ways to do it:
<u>Way #1:</u>
We all know about the law of conservation of energy. So we know that the total energy coming out must be 250J, because that's how much energy is going in. The wasted energy is 75J, so the rest of the 250J must be the useful energy . . . (250J - 75J) = 175J useful energy.
(useful energy) / (energy supplied) = (175J) / (250J) = <em>70% efficiency</em>
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<u>Way #2: </u>
How much of the energy is wasted ? . . . 75J wasted
What percentage of the Input is that 75J ? . . . 75/250 = 30% wasted
30% of the input energy is wasted. That leaves the other <em>70%</em> to be useful energy.
Explanation:
90 kmhr—1 x 1000/3600 = 25ms—1
U = 0 ms—1
V = 25ms—1
t = 10 s
a = ?
a = V - U/t
a = 25 - 0/10
a = 25/10
a = 2.5 ms—1
A fire because you feed it wood, it lives longer but if you give it a drink, water, then it dies.
Answer: Conduction
Explanation: As ice melts,more sunlight is absorbed,as more sunlight is absorbed,the atmosphere heats up,as the atmosphere heats up,more ice melts. This whole process is known as CONDUCTION.
Conduction occurs when there is different temperature between two materials, when there exist a transfer energy(i.e transfer from higher-energy atoms in the hot region to the lower-energy atoms in the cold region). When the atmosphere is heated up due to sunlight,there is a rise in temperature which makes the ice to melt due to transfer of warmth it absorbed from sunlight.