Kineticist, abilities range and line of effects

Hello everyone, i would like to ask some questions my players and I have about some of the kineticist abilities as i have two in my party, An Earth single gate and a Water/wood Dual gate Kineticist.

lets say my Earth kineticist is underground and want to use Tremor in a spot 20 ft away from him, can he does it even if he doesn't have a clear line of effect of the spot or let's say he cast it at 30ft, but his 20ft under the ground and the spot ends in the air it goes off?

and the other one is for my Water/wood kineticist Tumbling Lumber, can he use the impulse to send the logs to the air to hit a flying creature?

Thanks and sorry, english not first language