Mindy needs the apparatus to be able to detect a change in area as small as 3.50 cm2 occuring over a time period of 1.50 s. if the minimum emf that can be reliably detected is 2.00 × 10 − 4 v, what is the magnitude of the minimum external magnetic field that would be needed from the solenoid?

Two forces produce equal torques on a door about the door hinge. the first force is applied at the midpoint of the door; the second force is applied at the doorknob. both forces are applied perpendicular to the door. which force has a greater magnitude?

If you put a helium-filled balloon in the refrigerator, what will happen?

Diego is trying to lift a piano to the second floor of his house. diego uses a pulley system and gives a big lift to the piano. the piano moves upward, then stops, and then it starts to fall to the ground. which list best describes the forces on the piano in the proper order? positive force → balanced force → negative force negative force → balanced force → positive force positive force → unbalanced force → negative force negative force → unbalanced force → positive force