Use the drop-down menus to complete the sentences describing what happens when the temperature of a fluid increases. the kinetic energy of the molecules . the speed of the molecules . the density of the fluid . the fluid .

Abumper car with a mass of 250 kg is traveling at a speed of 4 m/s. this bumper car collides and sticks to a second bumper car with a mass of 250 kg, which is initially at rest. what is the final speed of these two bumper cars after the collision, assuming they remain stuck together?