Answer:
a) 1500 j 
b) 3000 j 
c) 34.64 m/s 
Step-by-step explanation:
at halfway point 1/2 of the potential energy has been converted to kinetic energy 
so 1 /2 P E = 1500 j 
 it will still have the OTHER half of its PE 1500 j
c) PE will be entirely converted to KE when it is at the bottom
 KE = 1/2 m v^2 
 3000 = 1/2 (5)(v^2) show v = 34.64 m/s