A toroid with a square cross section 3.0 cm 3.0 cm has an inner radius of 25.0 cm. It is wound with 500 turns of wire, and it carries a current of 2.0 A. What is the strength of the magnetic field at the center of the square cross section

If a refrigerator is a heat pump that follows the first law of thermodynamics, how much heat was removed from food inside of the refrigerator if it released 380j of energy to the room?

Awater-filled u-tube manometer is used to measure the pressure inside a tank that contains air. the water level in the u-tube on the side that connects to the tank is 5 ft above the base of the tank. the water level in the other side of the u-tube (which is open to the atmosphere) is 2 ft above the base. determine the pressure within the tank.

You have two photos of a person walking. one shows the person at the corner of third and main streets, the other shows the person at the corner of tenth and main streets. there are lampposts at every corner in this town, and the first picture shows it to be 10: 32: 00 exactly. the second picture shows it to be 10: 49: 30. you know three facts: (1) all of the clocks are synchronized; (2) there are exactly 12 equal-sized blocks per kilometer in this town; and (3) the streets that cross main in this area are numbered consecutively, with no interruptions. what is the person’s average speed in kilometers per hour?