Astudent wants you to demonstrate that an electric current will produce a magnetic field. which set of objects could be used to demostrate this?
a. a battery, a coil of wire and a compass. eliminateb)a compass, some paper clips and a battery.
c. a battery, an iron nail and a long copper wire.
d. an iron nail, a permanent magnet and a battery.

Na food processing facility, a spherical container of inner radius r1 5 40 cm, outer radius r2 5 41 cm, and ther- mal conductivity k 5 1.5 w/m · k is used to store hot water and to keep it at 100°c at all times. to accomplish this, the outer surface of the container is wrapped with a 800-w electric strip heater and then insulated. the temperature of the inner surface of the container is observed to be nearly 120°c at all times. as- suming 10 percent of the heat generated in the heater is lost through the insulation, (a) express the differential equation and the boundary conditions for steady one-dimensional heat conduction through the container, (b) obtain a relation for the variation of temperature in the container material by solving the differential equation, and (c) evaluate the outer surface tempera- ture of the container. also determine how much water at 100°c this tank can supply steadily if the cold water enters at 20°c.

Against his financial advisor's advice, frank has decided to invest his money in some risky stocks because he once made quite a bit of money in the stock market. his decision illustrates a. the representativeness heuristic b. overconfidence c. the availability heuristic d. confirmation bias select the best answer from the choices provided

Avector a⃗ has a length of 8.6 m and points in the negative x direction. find the x component of the vector −3.7a⃗ .