Two trains are moving towards each other from opposite directions. One is travelling at 80km/h and one is travelling at 70km/h. What is the speed of the two trains relative to each other in km/h? Explain how you came to this answer and show your working out.

Which diagram correctly demonstrates the various forces acting on a ball moving horizontally with some speed?

An insulated 40 ft^3 rigid tank contains air at 50 psia and 120°f. a valve connected to the tank is now opened, and air is allowed to escape until the pressure inside drops to 25 psia. the air temperature during this process is kept constant by an electric resistance heater placed in the tank. determine the electrical work done during this process.

This punnett square shows the cross between two pants. one parent has round seeds (rr). and the other parent has wrinkled seeds (rr) which best describes their offspring as shown in this cross?