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3 years ago

14

g An electric hot plate raises its own internal energy and the internal energy of a cup of water by 9000J, and there is at the s

ame time 2700J transferred to the cooler air. How much energy was transferred to the hot plate in the form of electricity

1 answer:

DochEvi [55]3 years ago

3 0

Answer:

11700j

Explanation:

add the two because the plate has to maintain the temp.

2700+9000=11700

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geniusboy [140]

Explanation:

Given that,

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Explanation:

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horsena [70]

Answer:

D.None of these

Explanation:

The derivation of acceleration formula:

Let us call the 5kg mass $m_2$ and the 4kg mass $m_1$ . If the tension in the string is $T$ then for the mass $m_2$

(1). $T-m_2g=-m_2a$ <em>(the negative sign on the right side indicates that acceleration is downwards)</em>

And for the mass $m_1$

(2). $T-m_1g =m_1a$ <em> (the acceleration is upwards, hence the positive sign)</em>

Solving for $T$ in the 2nd equation we get:

$T =m_1a+m_1g$ ,

and putting this into the 1st equation we get:

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$\boxed{a= \dfrac{(m_2-m_1)}{(m_1+m_2)} g}$

Back to the question:

Using the formula for the acceleration we find

$a= \dfrac{(5kg-4kg)}{(5kg+4kg)} g$

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3 years ago

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myrzilka [38]

The centripetal acceleration is given by
$a_c = \frac{v^2}{r}$
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For the car in this problem, $a_c = 15.625 m/s^2$ and r=40 m, so we can re-arrange the previous equation to find the velocity of the car:
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3 years ago

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laila [671]

Answer:

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Explanation:

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Thus, the arrow reaches at maximum height after 2 seconds.

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3 years ago