Can someone give me an example of a machine that uses a pulley ramp system? Multiple examples would be appreciated :)

bicycle wheels

roller skates

doorknob

A wheel that has a rope wrapped around it

the answer is d

lies a supermassive black hole called sagittarius a*, or sgr a* for short.

r=rho l/a where a is the area, l is the length and rho is resistivity so the greater the area the lesser the resistance thats why the earth pin is thicker bcos current follow the shortest path, so less resistive .