PLS HELP ME!!! The engine cars that pull high-speed trains usually taper to a point in front, as shown in the illustration. How does this shape change the forces acting on the moving engine car?

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?

Why do astronauts in the space shuttle weigh less?

Which body part transports oxygen removes waste materials in carries nutrients to the body as part of the circulatory system