ANSWER
20 N
EXPLANATION
Torque produced by a force F perpendicular to a lever arm with length r is:
[tex]\tau=F\cdot r[/tex]In this case we have to find F, when τ = 500 N*cm and r = 25cm:
[tex]500Ncm=F\cdot25\operatorname{cm}[/tex]Solving for F:
[tex]F=\frac{500Ncm}{25\operatorname{cm}}=20N[/tex]To produce a torque of 500N*cm, a perpendicular force of 20N must be applied
