Ahot air balloon rising vertically is tracked by an observer located 7 km7 km from the lift‑off point. at a certain moment, the angle between the observer's line of sight and the horizontal is ,π5, and it is changing at a rate of 0.2 rad/min.0.2 rad/min. how fast is the balloon rising at this moment? let yy be the height of the balloon (in km), be time (in minutes), and thetaθ the angle between the line‑of‑sight and the horizontal (in radians). (use decimal notation. give your answer to two decimal places.)

2.22/3.33 points | previous answers tamucolphysmechl1 4.pre.002. ask your teacher my notes question part points submissions used on a frictionless air track, a blue glider with mass 0.200 kg is moving to the right with a speed of 8.00 m/s. it strikes a red glider that has mass 0.600 kg and that is initially at rest. after the collision, the blue glider is moving to the left with a speed of 2.40 m/s. (a) what are the magnitude and direction of the velocity of the red glider after the collision? magnitude 3.33 m/s correct: your answer is correct. direction correct: your answer is correct. (b) is this collision elastic?

Lymphocytes known as blastocysts make antibodies that fight infection. select the best answer from the choices provided t f

As part of an industrial process, air as an ideal gas at 10 bar, 400k expands at steady state through a valve to a pressure of 4 bar. the mass flow rate of air is 0.5 kg/s. the air then passes through a heat exchanger where it is cooled to a temperature of 295k with negligible change in pressure. the valve can be modeled as a throttling process, and kinetic and potential energy effects can be neglected. (a) for a control volume enclosing the valve and heat exchanger and enough of the local surroundings that the heat transfer occurs at the ambient temperature of 295 k, determine the rate of entropy production, in kw/k. (b) if the expansion valve were replaced by an adiabatic turbine operating isentropically, what would be the entropy production? compare the results of parts (a) and (b) and discuss.