Given :
Accleration ( a ) = g sinθ
Velocity ( v ) = ( 10 g h / 7 )1/2
From v = u + at
u = 0
t = v / a
= [ ( 10 g h / 7 )1/2 / g sinθ ]
= 1.19 (gh)1/2 / gsinθ ----- ( 1 )
v/ = ( 2 g h ) 1/2
t/ = v/ / a
= ( 2 g h ) 1/2 / g sinθ
= 1.4 (gh)1/2 / gsinθ ------ ( 2 )
from ( 1 ) & ( 2 )
t/ / t = ( 2 g h ) 1/2 / g sinθ / [ ( 10 g h / 7 )1/2 / g sinθ ]
t/ > t
I hope it helps you