1. What is centripetal acceleration?
2. How does the law of displacement work in design?
3. Two identical cars collide head on. Each car is traveling at 100 km/h. The impact force on each car is the same as hitting a solid wall at:
(a) 100 km/h
(b) 200 km/h
(c) 150 km/h
(d) 50 km/h
[H/T real-world physics]