Which question asks for an opinion? A. Can people who visit Mars use the resources there to fuel a return
trip to Earth?
B. How much more radiation reaches Mars's surface than reaches
Earth's surface?
C. Is it a good idea to try to establish human colonies on Mars?
D. Is it possible to establish a human colony on Mars?

A980-kg sports car collides into the rear end of a 2300-kg suv stopped at a red light. the bumpers lock, the brakes are locked, and the two cars skid forward 2.6m before stopping.the police officer, estimating the coefficient of kinetic friction between tires and road to be 0.80, calculates the speed of the sports car at impact. what was that speed?