A. You measure power on watts.
B. Non-renewable
C.renewable
D. Joules
E. Fossil fuels
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 :)
Considering north as positive Y axis
First 10 miles north means a positive 10 displacement along y direction
Second 20 miles south means a negative 20 displacement along y direction
Third 5 miles south means a positive 5 displacement along y direction
So total displacement = 10 - 20 + 5 = -5 miles displacement
So position vector of the final position = - 5 j