A 1000 kg car is moving at 20 m/s when it collides with a 2000 kg moving at 15 m/s in the same direction. The two cars stick together and move off together as one giant wreck. What is the velocity of the wreck? a. 5 m/s b. 10 m/s c. 16.7 m/s d. 17.5 m/s

If the force on an object is in the negative direction, the work it does on the object must be [2 points a) negative. b) positive c) the work could be either positive or negative, depending on the direction the object moves

Convection currents are caused by differences in what two things?

On a frictionless air track, a blue glider with mass 0.200 kg is moving to the right with a speed of 8.00 m/s. it strikes a red glider that has mass 0.600 kg and that is initially at rest. after the collision, the blue glider is moving to the left with a speed of 3.00 m/s.(a) what are the magnitude and direction of the velocity of the red glider after the collision? (b) is this collision elastic?