What does the term discrediting mean?

When applying kirchhoff's rules, one of the essential steps is to mark each resistor with plus and minus signs to label how the electric potential changes from one end of the resistor to the other. the circuit in the drawing contains four resistors, each marked with the associated plus and minus signs. however, one resistor is marked incorrectly. which one is it?

Atruck of mass 3000 kg moves around an unbanked comer of radius 87.4 m. if the coefficient of static friction between the truck tires and the road is 0.800, what is the maximum speed that the truck can move without slipping, in units of m/s?

Eddy whose mass is 55kg climbs up the 1.50 meter high stairs in 2s. calculate eddy’s power rating