A 6,600 kg train car moving at +2.0 m/s bumps into and locks together with one of mass 5,400 kg moving at −3.0 m/s . What is their final velocity? −1.0 m/s

−0.25 m/s

+0.50 m/s

+2.5 m/s

Identify two factors that determine the rate of stream erosion

Curious carl calculated the density of a cube to be 4.50 g/cm3. what is the density of the cube in g/l?

Moon effect. some people believe that the moon controls their activities. if the moon moves from being directly on the opposite side of earth from you to being directly overhead, by what percentage does (a) the moon's gravitational pull on you increase and (b) your weight (as measured on a scale) decrease? assume that the earth–moon (center-to-center) distance is 3.82 × 10^8 m, earth's radius is 6.37 × 10^6 m, moon's mass is 7.36 × 10^22 kg, and earth's mass is 5.98 × 10^24 kg.