Answer:
tectonic plates move in opposite direction
Tectonic plates are not necessarily moving in opposite directions, but if there directions are different they form plate boundaries. If they were moving in the same direction they would become the same plate. The more opposite the direction, the more obvious the fault.
Examples of plate boundaries:
Divergent: moving away from each other - mid-Atlantic ridge
Convergent: moving towards each other - the Himalayas (Indian plate subducting under the Eurasian plate forcing up the mountains)
Transform: sliding laterally along each other - San Andreas fault
C because they are both going in a constant speed
Answer:
Well if they playing a game like that
After it's long use, the bridge continuously undergoes through alternating strains. in result, the elastic strength of the bridge gets reduced. while the process goes on the bridge makes elastic fatigue and a permanent change happens which makes it collapse which is the reason why bridges are declared unsafe after a long use :)
