Atank is filled with 1000 liters of pure water. brine containing 0.07 kg of salt per liter enters the tank at 7 liters per minute. another brine solution containing 0.03 kg of salt per liter enters the tank at 10 liters per minute. the contents of the tank are kept thoroughly mixed and the drains from the tank at 17 liters per minute.

a. determine the differential equation which describes this system. let s(t)denote the number of kg of salt in the tank after t minutes. then

Energy is the ability to do work which measures what

An astronaut in space cannot use a scale or balance to weigh objects because there is no gravity. but she does have devices to measure distance and time accurately. she knows her own mass is 77.4 kg , but she is unsure of the mass of a large gas canister in the airless rocket. when this canister is approaching her at 3.50 m/s , she pushes against it, which slows it down to 1.30 m/s (but does not reverse it) and gives her a speed of 2.60 m/s . what is the mass of the canister?

Which body is in equilibrium? (1) a satellite orbiting earth in a circular orbit (2) a ball falling freely toward the surface of earth (3) a car moving with a constant speed along a straight, level road (4) a projectile at the highest point in its trajectory