A 42,000-kg train car travelling at 10 m/s toward another train car. After the two cars collide, they couple together and move along at 6 m/s. What is the mass of the second train car?
and omheds itself in the wood. The piece of lumber?

Iwill give brainliest if you answer right : )

Under the action of a constant force an object accelerates at 7.8 m/s2. what will the acceleration be if (a) the force is halved? (b) the object's mass is halved? (c) the force and the object's mass are both halved? (d) the force is halved and the object's mass is doubled?

Apropagating wave in space with electric and magnetic components. these components oscillate at right angles to each other. it may travel in a vacuum. determine the term.