Answer:
Step-by-step explanation:
Acceleration of the person is same as the acceleration of the elevator
So here when elevator is moving at uniform velocity so we can say that acceleration of the elevator will be zero
so net force on the person must be zero as per Newton's 2nd law
![F_(net) = ma](https://img.qammunity.org/2019/formulas/physics/college/n14iuq4f92v3v6j16ed685pfrrveyucj30.png)
so here force on the person is given as
![F_n - mg = ma](https://img.qammunity.org/2019/formulas/physics/high-school/ixsg0aw4spzeo4d44qnsjp3r5kpn6s54nk.png)
here we have
![a = 0](https://img.qammunity.org/2019/formulas/mathematics/high-school/jfm84k85ogag6n2p56hncptn8t8qo9hf28.png)
![F_n = mg](https://img.qammunity.org/2019/formulas/physics/high-school/ag51z36h7bpr07dei0rzvidm454jqi90vh.png)
as we know that
![mg = 500 N](https://img.qammunity.org/2019/formulas/physics/high-school/ftvgxpfjtwyh9xu18ry06gyv3i6gp4d6aa.png)
![F_n = 500 N](https://img.qammunity.org/2019/formulas/physics/high-school/k1cnr4g14p81wfk4vgwwqn0yo0vlg2o8bh.png)
so the floor will exert 500 N force on man