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makvit [3.9K]
3 years ago
11

A square is cut out of a copper sheet. Two straight scratches on the surface of the square intersect forming an angle theta. The

square is heated uniformly. As a result, the angle between the scratches?a) increasesb) decreasesc) stays the samed) depends on whether theta is obtuse or acute
Physics
1 answer:
GarryVolchara [31]3 years ago
5 0

Answer:

<em>a) increases</em>

Explanation:

Almost all substance or material undergoes expansion due to heating. Heat gives thermal energy to the molecules of a substance increasing their body temperature. The temperature of a substance is the measure of the average kinetic energy of the molecules of that substance. When the temperature of a substance increases, the molecules begin to agitate and try to move far from each other, leading to either a linear, area, or cubic expansion, or all three of them. Metals like copper expand very well on heating, and their expansion is relatively minute, but very observable. When the face of such a copper is scratched to give and angle, heating the copper uniformly will cause the copper to expand, leading to an increase in the angle formed.

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seropon [69]

Answer:

<em>The bullet was 0.52 seconds in the air.</em>

Explanation:

<u>Horizontal Motion </u>

It occurs when an object is thrown horizontally with a speed v from a height h.

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To calculate the time the object takes to hit the ground, we use the following equation:

\displaystyle t=\sqrt{\frac{2y}{g}}

Note it doesn't depend on the initial velocity but on the height.

The bullet is fired horizontally at h=1.3 m, thus:

\displaystyle t=\sqrt{\frac{2\cdot 1.3}{9.8}}

\displaystyle t=\sqrt{\frac{2.6}{9.8}}

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Ivahew [28]
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A 120 V fish-tank heater is rated at 130W. Calculate (a) the current through the heater when it is operating, and (b) its resist
7nadin3 [17]

Explanation:

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b) The resistance <em>R</em><em> </em>of the heater is

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Explanation:

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(see diagram below)

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