Air enters a tank through a pipe with cross-sectional area of 0.2 ft2 with a velocity of 15 ft/s and a density of 0.03 slug/ft3 . Air leaves with a velocity of 5 ft/s and a density equal to that in the tank (which is homogeneously mixed). The initial density of the air in the tank is 0.02 slug/ft3 . The tank volume is 20 ft3 and cross-sectional area of the exit pipe is 0.4 ft2 . Find ��/�� at t = 0

Aroller coaster car moving at a velocity of 30 meters/second has a momentum of 2.5 x 10^4 kilogram meters/second. what is its mass?

An airplane flying parallel to the ground undergoes two consecutive displacements. the first is 76 km at 39.8◦ west of north, and the second is 156 km at 59.9◦ east of north. what is the magnitude of the plane’s total displacement? answer in units of km. 020 (part 2 of 2) 10.0

Next a skier is pulled by a tow rope up a frictionless ski slope that makes an angle of 15 with the horizontal. the rope moves parallel to the slope with a constant speed of 0.69 m/s. the force of the rope does 800 3 of work on the skier as the skier moves a distance of 8.4 m up the incline. (a) if the rope moved with a constant speed of 2.2 m/s how much work would the force of the rope do on the skier as the skler moved a distance of 8.4 m up the incline? at what rate is the force of the rope doing work on the skier when the rope moves with a speed of (b) 0.69 m/s and (c) 2.2 m/s?