Answer:
a) The planet experiences a centripetal force towards its star
b) The universal attractive force (Gravitational force)
c)None of these choices are true.
Explanation:
This problem raise several claims, let's review some aspects of circular motion
F = m a
the centripetal acceleration is
a = v² / r
where v is the speed (modulus of velocity) that is constant and r is the radius
The direction of the acceleration is perpendicular to the motion.
Let's review the different claims
Part a) the orbital velocity is constant
The correct statement is: The planet experiences a centripetal force towards its star
Part b) what is the centripetal force
The correct statement: The universal attractive force (Gravitational force)
Part c) which statement is true
1) False. There can be no tangential force
2) False. There is a centripetal force that creates the movement, but there is no centrifugal force because the system is accelerated and there is no tangential force because the movement is circular.
3) False. There is no tangential force
4) True none is true
5) False. There is a force because movement has acceleration
