Transverse, I think. I may be wrong.
Explanation:
We have,
Speed of plane a is 900 km/h
Plane b is moving at a rate of 
It is required to find which plane is faster. To find which plane is faster, we need to compare their speeds.
Speed of a plane a is 900 km/h and that of plane b is 50 km/h. So, we can say that plane a is moving faster.
Mechanical energy equals the sum of potential and kinetic energy. During the process, all PE converts into KE, assuming air resistance is neglected. So, the mechanical energy does not change and is equal to the initial potential energy.
ME
=mgh
=0.005 x 9.81 x 3
=0.147J
Yes the velocity changes. Because velocity changes with direction. The object is moving around a gentle curve. The curve is not linear it is curve the direction changes a bit so obviously the velocity also changes but not much. Juts a minor change. Depends on how much curve the highway is.
I assume there are choices to this question that you forgot to include. No matter, I could just lay out the concept so that you can understand the gist.
The best way to approach this is to know the definition of momentum. In physics, momentum is always defined in terms of equation. For momentum, it is the product of the mass and velocity. Therefore, any increase of these two parameters would promote greater momentum. The greater the mass paired with the faster the velocity, the greater the momentum.
