A 1500-kg car traveling due north with a speed of 25 m/s collides head-on with a 4500-kg truck traveling due south with a speed of 15 m/s. The two vehicles stick together after the collision. What is the total momentum of the system prior to the collision

How does the image distance (di) of a convex lens compare with the image distance of a concave lens? a. the image distance of the convex lens is positive, and that of the concave lens is negative. b. both are negative for a virtual image. c. both are positive for a virtual image d. the image distance of the convex lens is negative, and that of the concave lens is positive.

The volume of a gas is halved during an adiabatic compression that increases the pressure by a factor of 2.5. what is the specific heat ratio? show the math steps .

6–43 a food department is kept at 2128c by a refrigerator in an environment at 308c. the total heat gain to the food department is estimated to be 3300 kj/h and the heat rejection in the condenser is 4800 kj/h. determine the power input to the compressor, in kw and the cop of the refrigerator.