An astronaut of mass 150 kg is floating freely (at rest) in outer space. She is holding a 25 kg can (not part of her mass mentioned earlier). She throws the can forward with a velocity of 12 m/s. How fast will she move backwards after she throws the can?

A5 foot by 5 foot box culvert is buried 6 feet beneath the surface of the ground. a crosssection of this very long culvert (into and out of the page) is illustrated below. assume that the soil in which the culvert is buried has the following properties: jt = 120 pcf, w = 12%, ko = 0.50, ka = 0.33, and kp = 3.00. calculate the total horizontal force per unit length of culvert (fh) felt on one of the vertical faces of the culvert.