A rubber-wheeled 50 kg cart rolls down a 60 degree concrete incline. Coefficient of rolling friction between rubber and concrete is μr = 0.02. A) What is the cart's acceleration if rolling friction is neglected?
B) What is the cart's acceleration if rolling friction is included?

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.

Since the energy was not raising the temperature of the water during these segments, what was the energy used to do instead? your answer must include an explanation of what is happening to the molecules.

Which of the following statements correctly describes a transformer?