4. A truck with mass of 3000 kg traveling with a velocity of 15 m/s hits a car at rest. After the collision, the truck moves with a velocity of 10 m/s. If the car has a mass of 2000 kg and
the two vehicles do not stick together, how fast is the car moving after the collision? Is this
an elastic or inelastic collision?

What can change the speed of sound as it travels through the ocean? a. salinity only b. density and salinity c. salinity and distance from land d. density and distance from land

In an electric circuit, what is one material that the connector can be made of? a. rubber b. aluminum foil c. glass d. wood

Tornadoes form in unusually violent thunderstorms when there is sufficient (1) instability and (2) wind shear present in the lower atmosphere. elaborate on what does instability mean when discussing the formation of a tornado? a) dry air in the middle atmosphere being rapidly cooled by rain b) winds at all levels of the atmosphere are strong and turn with height c) an isolated strong thunderstorm just ahead of a squall line that merges with the squall line d) very warm, humid conditions in the lower atmosphere; cooler than usual conditions in the upper atmosphere