Answer:

Explanation:
A closed system is a system where exists energy interactions with surroundings, but not mass interactions. If we neglect any energy interactions from boundary work, heat, electricity, magnetism and nuclear phenomena and assume that process occurs at steady state and all effects from non-conservative forces can be neglected, then the equation of energy conservation is reduce to this form:
(1)
Where:
- Change in kinetic energy of the system, measured in joules.
- Change in gravitational potential energy of the system, measured in joules.
If we know that
and
, then we get the following equation:
(2)
Where
and
stands for initial and final states of each energy component.
Hence, the right answer is 
Given that,
Mass of the object, m = 1 kg
It moves in a circle of radius 0.5 m with a speed of 5 m/s
To find,
The direction of the acceleration.
Solution,
Whenever an object moves in a circular path, the only force that acts on its is centripetal force which is given by the formula as follows :

The centripetal acceleration acts in the direction of force. It acts along the radius of the circular path. In this figure, the direction of the acceleration is shown at point d.
Step 1, ask a question
step 2, do research
step 3, make a hypothesis
step 4, test your hypothesis with an experiment
step 5, analyze your data
step 6, make a conclusion