Work Done By Force with No Friction Determine the work that is being done by tension in pulling the box 50.0 cm along the table. Also determine the speed of the box after traveling the specified distance. 5.9 N 2.8 kg​

Aresistor with an unknown resistance is connected in parallel to a 9 ω resistor. when both resistors are connected in parallel to an emf source of 21 v, the current through the unknown resistor is measured with an ammeter to be 4 a. what is the resistance of the unknown resistor? answer in units of ω.