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zmey [24]
2 years ago
15

Which letter explains why no machine is 100 percent efficient.

Physics
1 answer:
kondaur [170]2 years ago
4 0

Answer:

A

Explanation:

Think about rubbing your hands together- the friciton produces heat

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7. A block of copper of unknown mass has an initial temperature of 65.4oC. The copper is immersed in a beaker containing 95.7g o
dolphi86 [110]

Answer:

37.34372 kg

Explanation:

m = Mass

\Delta T = Change in temperature

1 denotes water

2 denotes copper

c = Heat capacity

Heat is given by

Q=mc\Delta T

In this case the heat transfer will be equal

m_1c_1\Delta T_1=m_2c_2\Delta T_2\\\Rightarrow m_2=\frac{m_1c_1\Delta T_1}{c_2\Delta T_2}\\\Rightarrow m_2=\frac{95.7\times 4.18(24.2-22.7)}{0.39(65.4-24.2)}\\\Rightarrow m_2=37.34372\ kg

Mass of copper block is 37.34372 kg

5 0
3 years ago
A 2 kilogram bowling ball is 2.5 meters off the ground on a post when it falls just before it reaches the ground it is traveling
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I need the answer too
7 0
3 years ago
A 250 - ω resistor is connected in series with a 4.80 - μf capacitor. the voltage across the capacitor is vc=(7.60v)⋅sin[(120rad
galben [10]
<span>553 ohms The Capacitive reactance of a capacitor is dependent upon the frequency. The lower the frequency, the higher the reactance, the higher the frequency, the lower the reactance. The equation is Xc = 1/(2*pi*f*C) where Xc = Reactance in ohms pi = 3.1415926535..... f = frequency in hertz. C = capacitance in farads. I'm assuming that the voltage and resistor mentioned in the question are for later parts that are not mentioned in this question. Reason is that they have no effect on the reactance, but would have an effect if a question about current draw is made in a later part. With that said, let's calculate the reactance. The 120 rad/s frequency is better known as 60 Hz. Substitute known values into the formula. Xc = 1/(2*pi* 60 * 0.00000480) Xc = 1/0.001809557 Xc = 552.6213302 Rounding to 3 significant figures gives 553 ohms.</span>
6 0
4 years ago
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Look at the picture above and scientifically explain how eating a hamburger can cause energy transformation in three ways within
sergejj [24]

Answer:

CLAIM: When you eat the hamburger, your body uses it and breaks it down which is chemical energy than use that food for energy for mechanical energy which makes thermal energy

EVIDENCE: This happens every day to people across the world and also it is scientifically proven

REASONING: The reason why this evidence supports it is because as I said  it happens everyday and when you feel energized after and apple after you were lazy that just happened

Explanation:

7 0
3 years ago
A liquid does not have a definite shape, but it does have a definite volume.<br><br> TRUE or FALSE
il63 [147K]
Well it's <span>False. They have a definite volume, but not a definite shape. GASES have neither a definite shape nor definite volume! Hope I could help!</span>
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3 years ago
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