Calculate the mechanical advantage of a ramp if the box you are trying to move has a mass of 10 kilograms, the board is 15 feet long and the height of the ramp is 5 feet.

Alfred pushes on a heavy box, but cannot move it. the box has a lot of inertia motion friction gravity

Which best describes the first law of thermodynamics as compared to the second law of thermodynamics? a. the first law describes how thermal energy is conserved but not the direction it moves. b. the first law describes the direction thermal energy moves but not how it is conserved. c. the first law describes how thermal energy can be created but not how it can be destroyed. d. the first law describes how thermal energy can be destroyed but not how it can be created.

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?