Select the correct choice(s) : - Vidyadip

MCQ

Select the correct choice(s) :

A
The gravitational field insideaspherical cavity,with inaspherical planet must be non zero and uniform.
B
When a body is projected horizontally at an appreciable large height above the earth, with a velocity less than for a circular orbit, it will fall to the earth along a parabolic path.
✓
Abody of zero total mechanical energy placed in a gravitational field will escape the field
D
Earth’s satellite must be in equatorial plane .

✓

Answer

Correct option: C.

Abody of zero total mechanical energy placed in a gravitational field will escape the field

c
Gravitational field is conservative field, total mechanical energy is conserved. If a body is in gravitational field with $U+K=0 \rightarrow K=-U \rightarrow(1)$ i.e. Kinetic energy is non zero.So, it will move away from the field till its kinetic energy is also zero.

If $K=0 \rightarrow U=0$ from $(1).$ But, $U=0$ is at $\infty$ and thus the body escapes the field.

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