Light travels in a straight line at a constant speed of 3,0 x 108 m/s for 4,1 years to reach the earth from the nearest star 3.9 x 10"3 km away. What is
its acceleration?

As the velocity of light is constant so the acceleration of the light is equal to zero.

a= dv/dt

Explanation:

the working equation for the angular size is the product of the physical size and 360 degrees divided by the product of two pi and distance from earth. the minimum size would be 0.559 degrees while the maximum size would be 0.49 degrees. 

answer would be letter choice (a),   a ball resting on a shelf. would be another example of potential energy   >   stored energy > not moving.

a ball spinning on a finger   >   kinetic energy > moving energy

a ball rolling on the ground   >   kinetic energy   > moving energy

a   ball flying through the air   > kinetic energy   >   moving energy

hope that                                         : )