Define one second time

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? a.positive force, balanced force, negative force b.negative force, balanced force, positive force c.positive force, unbalanced force, negative force d. negative force, unbalanced force, positive force

Acommon procedure for measuring the velocity of an airstream involves the insertion of an electrically heated wire (called a hot-wire anemometer) into the airflow, with the axis of the wire oriented perpendicular to the flow direction. the electrical energy dissipated in the wire is assumed to be transferred to the air by forced convection. hence, for a prescribed electrical power, the temperature of the wire depends on the convection coefficient, which, in turn, depends on the velocity of the air. consider a wire of length l = 20 mm and diameter d = 0.5 mm, for which a calibration of the form v = 6.25 ă— 10â’5 h2 has been determined. the velocity v and the convection coefficient h have units of m/s and w/m2 â‹… k, respectively. in an application involving air at a temperature of tâž = 25â°c, the surface temperature of the anemometer is maintained at ts = 75â°c with a voltage drop of 5 v and an electric current of 0.1 a. what is the velocity of the air?

Which phenomena are transmissions of light? refraction, polarization, and scattering polarization, scattering, and reflection reflection, refraction, and absorption scattering, absorption, and refraction