A conducting rod of length L moves on two horizontal frictionless rails, as in Figure P20.18. A constant force of magnitude 1.70 N moves the bar at a uniform speed of 2.10 m/s through a magnetic field B that is into the page. (a) What is the current in an 14.00 ? resistor R? A conducting rod of length L moves on two horizontal frictionless rails, as in Figure P20.18. A constant force of magnitude 1.70 N moves the bar at a uniform speed of 2.10 m/s through a magnetic field B that is into the page. (a) What is the current in an 14.00 ? resistor R? (c) What is the mechanical power delivered by the constant force? A conducting rod length L moves on two horizont A conducting rod of length L moves on two horizontal frictionless rails, as in Figure P20.18. A constant force of magnitude 1.70 N moves the bar at a uniform speed of 2.10 m/s through a magnetic field B that is into the page. (a) What is the current in an 14.00 ? resistor R? A conducting rod of length L moves on two horizontal frictionless rails, as in Figure P20.18. A constant force of magnitude 1.70 N moves the bar at a uniform speed of 2.10 m/s through a magnetic field B that is into the page. (a) What is the current in an 14.00 ? resistor R? (c) What is the mechanical power delivered by the constant force?