Thank you for the opportunity to help you with your question!

In question 'a' the direction of the arrow will be on option will be 'c' because centripetal force of an object is perpendicular to the motion of the moving object

in question 'b' the the answer will be 'd ' since the centripetal force of an object will always be perpedicular to the motion of the object

ke =0.5* mvv

12kg=12000g

v=5m/s

0.5*12000*5*5

=150000 joules

PE=mgh

2kg

150m

pe=2*10*150

=3000 joules

power=w/time

energy=500 joules

time=10 s

500/10

=50W

Regards

Please let me know if you need any clarification. I'm always happy to answer your questions.