4. How would our lives be affected if Einstein's postulates were true but the speed of light were 100 km/h? (Hint: Consider simple specific examples, such as the nature of a highway journey at 60 km/h. What difficulty arises as we try to accelerate the car to 110 km/h?) 5. "Matter has broken the sound barrier but will not be able to exceed the speed of light." Explain this statement