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Ede4ka [16]
2 years ago
14

.A 0.2-kg aluminum plate, initially at 20°C, slides down a 15-m-long surface, inclined at a 30 angle to the horizontal. The forc

e of kinetic friction exactly balances the component of gravity down the plane so that the plate, once started, glides down at constant velocity. If 90% of the mechanical energy of the system is absorbed by the aluminum, what is its temperature increase at the bottom of the incline? (Specific heat for aluminum is 900J/kg⋅°C.)
a. 0.16 C°b. 0.07 C°c. 0.04 C°d. 0.03 C°
Physics
1 answer:
Ainat [17]2 years ago
7 0

To solve this problem, it is necessary to apply the concepts related to Work according to the Force and distance, as well as the concepts related to energy lost-or gained-by heat. Mathematically the energy corresponding to heat is given as:

Q = mC_p(\Delta T)

Where,

m = mass

C_p= Specific heat

\Delta T = Change in Temperature

At the same time the Work made by the Force and the distance is given as:

W = F*d \rightarrow W=mg*d

As the force is applied at an angle of 30 degrees, the efficient component would be given by the vertical then the work / energy would be determined as:

W = mg*dsin(30)

W = (15m)(0.2kg)(9.81)(sin30)

W = 13.24J

Now this energy is used to heat the aluminum. We can find the change at the temperature as follow:

Q = mC_p(\Delta T)

13.24 = (0.2)(900)(\Delta T)

\Delta T = 0.0736 \°C

Therefore the correct answer is B.

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Answer:

<h2>30 J</h2>

Explanation:

The work done by an object can be found by using the formula

workdone = force × distance

From the question

force = 6 N

distance = 5 m

We have

workdone = 6 × 5 = 30

We have the final answer as

<h3>30 J</h3>

Hope this helps you

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A ball thrown horizontally from a point 30.0 m above the ground strikes the ground after travelling a horizontal distance of 18.
AURORKA [14]

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\begin{cases}18.0=v_{0x}t\\0=30.0-4.9t^2\end{cases}

From the second equation, we can show that the ball travels for about t=2.47 seconds, which means it was initially thrown with a horizontal velocity of

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7 0
3 years ago
7. What causes waves to bend?
lesantik [10]

Answer:

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3 years ago
Read 2 more answers
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