UNIVERSE
SATELLITESICY BODIES
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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The acceleration of S is always directed towards the centre of the earth
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The angular momentum of S about the centre of the earth changes in direction, but its magnitude remains constant
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The total mechanical energy of S varies periodically with time
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The linear momentum of S remains constant in magnitude
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Detailed explanation-1: -The mass of the satellite is very small compared to the mass of the earth. Then. the acceleration of S is always directed towards the centre of the earth. the angular momentum of S about the centre of the earth changes in direction, but its magnitude remains constant.
Detailed explanation-2: -The satellite is moving the fastest at the low point of an elliptical orbit. The low point of the orbit is called the perigee. The high point of the orbit, when the satellite is moving the slowest, is called the apogee.
Detailed explanation-3: -Satellites travel in elliptical orbits about their planet. If the speed of a satellite is suddenly increased the shape of the elliptical orbit elongates. If a satellite has enough velocity to escape and never return to the planet the path it travels is a parabola or a hyperbola.
Detailed explanation-4: -If, however, the satellite is moving in the elliptical orbit AB (a = R + 1, 500; e = 0.09), the velocity at A will be 3.82 miles/sec., at B 4.59 miles/sec., with an average velocity in the orbit of 4.19 miles/sec., corresponding to the smaller a. Though the mean velocity is higher, the speed at A is smaller than before.
Detailed explanation-5: -If the orbital path of a satellite is circular, then its speed is constant and if the orbital path of a satellite is elliptical one, then its speed in its orbit is not constant.