Consider the air over a city to be a box 100 km on two sides that reaches up to an altitude of 1.0km. clean air is blowing into the box along one of its sides with a speed of 4 m/s. suppose an air pollutant with a degradation reaction rate k = 0.2 hr-1 is emitted into the box at a total rate of 10.0 kg/s.

if the windspeed in this above problem suddenly drops to 1 m/s, estimate the concentration of the pollutant two hours later.

You are traveling in a car going at a constant speed of 100km/h down a long, straight highway. you pass another car going in the same direction which is traveling at a constant speed of 80km/h. as measured from your car's reference frame this other car is traveling at −20km/h. what is the acceleration of your car as measured from the other car's reference frame? what is the acceleration of the other car as measured from your car's reference frame?

1. jay fills a wagon with sand (about 20 kg) and pulls it with a rope 30 m along the beach. he holds the rope 25° above the horizontal. the rope exerts a 20-n tension force on the wagon. how much work does the rope do on the wagon?

If the textbook weighs 19.6 newtons on venus,what is the strength of gravity on venus?