As 9h30, Osmar saiu de casa com sua bicicleta para visitar alguns amigos. Primeiramente, foi à casa de Odair, distante 12 km, chegando às 10h. Após conversar durante meia hora, Osmar se dirigiu à casa de Rosângela, mantendo velocidade constante de 20 km/h. Chegou lá às 11h30. Qual foi a velocidade escalar média de Osmar, em km/h, desde sua casa até a casa de Rosângela? Por favor, me ajudem
Quero resolução, please*

Askydiver weighing 140 lb (including equipment) falls vertically downward from an altitude of 19,000 ft and opens the parachute after 18 s of free fall. assume that the force of air resistance, which is directed opposite to the velocity, is of magnitude 0.55|v| when the parachute is closed and is of magnitude 14|v| when the parachute is open, where the velocity v is measured in ft/s. assume that acceleration due to gravity has magnitude 32 ft/s/s; remember that weight is the product of mass and gravitational acceleration. (a) find the speed of the skydiver when the parachute opens. (b) find the distance fallen before the parachute opens. (c) what is the limiting velocity vl after the parachute opens? (d) determine how long the sky diver is in the air after the parachute opens. (e) plot the graph of velocity versus time from the beginning of the fall until the skydiver reaches the ground.

How is sound energy produced a. vibrating objects b. objects being heated c. temperature differences d. stationary objects

Asmall object with mass 0.200 kg swings back and forth on the lower end of a light rope that is 3.00 m long. the upper end of the rope is attached to the ceiling. as the object swings through its lowest position, where the rope is vertical, the speed of the object is 5.80 m/s. at this point in the motion, what is the tension in the rope? (use g = 9.80 m/s2.)