Charlie wants to build a magnetic levitation train for his younger brother. Charlie has drawn a diagram of his train and has built the train. What should Charlie do next with his design? A. Test the device, get feedback from other people, and revise the design if needed.
B. Show his design to other people and get feedback before selling his design.
C. Publish his design in a magazine as is and wait for investors.
D. Test the device and sell it to the local veterinarian.

In raising a 6200-n piano with a pulley system, the movers note that, for every 2.2 m of rope pulled down, the piano rises 0.12 m . ideally, find the force required to lift the piano.

The membrane surrounding a living cell consists of an inner and an outer wall that are separated by a small space. assume that the membrane acts like a parallel plate capacitor in which the effective charge density on the inner and outer walls has a magnitude of 7.0 × 10-6 c/m2. (a) what is the magnitude of the electric field within the cell membrane? (b) find the magnitude of the electric force that would be exerted on a potassium ion (k+; charge = +e) placed inside the membrane.

In the circuit shown below, with each bulb holding a resistance of 60 ohms, how many amps of current are flowing? express your number as a decimal.