Let's start with the second question first. If the two forces aren't balanced, the truck will move in some direction. So the downward force of the truck must equal the upward force provided by the pavement pushing up.
Mass of truck = 9500 kg. Remember mass is directionless and it is not a force or weight. That truck would have a mass of 9500 kg anywhere in the universe.
Givens
m = 9500
a = 9.8
Force or weight = ?
Formula and Solution
F = m * a
F = 9500 * 9.8
F = 93100 N
Comment
That force does have a direction. It is down.
The balancing force (you call it the reaction force) going upward is 93100 N
