Answer:
∆PE = 749.7 J
At 0.9 m high, PE = 793.8 J
At 1.75 m high, PE = 1543.5 J
Answer:
c) At a distance greater than r
Explanation:
If G= Gravitational constant
M= Mass of earth
r= distance from earth center
then orbital speed is ;
v = 
==> v²=GM/r
If speed of first satellite = V₁
==> V₁² = GM/r
==> r = GM/V₁²
If speed of second satellite say V₂ is less than V₁ then square of V₂ will be less than square of V₁ , and hence GM will be divided by less number in case of second satellite, and hence will give greater value of r as compared to first satellite.
So our answer is c
Answer:
The focal length of the lens should be -51.5 cm (a concave lens).
Explanation:
The purpose of the lens is to make objects at 48.5 cm appear at the healthy near point. The healthy near point is 25.0 cm.
We use the lens formula

where <em>f</em> = focal length, <em>u</em> = object distance and <em>v</em> = image distance.
In this case, <em>u</em> = 48.5 cm and <em>v</em> = -25.0 cm.
<em>v</em> is negative because the image is virtual an not real. (Here, we are using the real-is-positive sign convention)


The negative sign indicates the lens is concave.
Answer:
From 0 -4 seconds the acceleration is positive. (The graph is going upwards.)
From 6-10 seconds the acceleration is negative. (The graph is going downwards.)
Answer: <u><em>C. Steel</em></u>
Explanation: <em><u>When a sound wave travels through a solid body consisting</u></em>
<em><u /></em>
<em><u>of an elastic material, the velocity of the wave is relatively</u></em>
<em><u /></em>
<em><u>high. For instance, the velocity of a sound wave traveling</u></em>
<em><u /></em>
<em><u>through steel (which is almost perfectly elastic) is about</u></em>
<em><u /></em>
<em><u>5,060 meters per second. On the other hand, the velocity</u></em>
<em><u /></em>
<em><u>of a sound wave traveling through an inelastic solid is</u></em>
<em><u /></em>
<em><u>relatively low. So, for example, the velocity of a sound wave</u></em>
<em><u /></em>
<em><u>traveling through lead (which is inelastic) is approximately</u></em>
<em><u /></em>
<em><u>1,402 meters per second.</u></em>
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