A baseball pitcher brings his arm forward during a pitch, rotating the forearm about the elbow. If the velocity of the ball in t
1 answer:
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Answer:
The ratio of the orbital time periods of A and B is
Solution:
As per the question:
The orbit of the two satellites is circular
Also,
Orbital speed of A is 2 times the orbital speed of B
(1)
Now, we know that the orbital speed of a satellite for circular orbits is given by:
where
R = Radius of the orbit
Now,
For satellite A:
Using eqn (1):
(2)
For satellite B:
(3)
Now, comparing eqn (2) and eqn (3):
The correct answer is:
Work is negative, the environment did work on the object, and the energy of the system decreases.
In fact, the work-energy theorem states that the work done by the system is equal to its variation of kinetic energy:
In this problem, the variation of kinetic energy is negative (because the final velocity is less than the initial velocity), so the work is negative, and this means that the environment did work on the object, and its energy decreased.