Two resistanceless rails rest 24 cm apart on a 4.0 ∘ ramp. They are joined at the bottom by a 0.70 Ω resistor. At the top a copper bar of mass 0.080 kg (ignore its resistance) is laid across the rails. The whole apparatus is immersed in a vertical 0.50 T field. Part A What is the terminal (steady) velocity of the bar as it slides frictionlessly down the rails