Question

Ralph is driving at a constant 70.0 mi/hr (31.3 m/s) along a straight section of Route 3 North. The car directly ahead of him is also moving at 70.0 mi/hr. The front bumper of Ralph's car is located 12.00 m from the rear bumper of the car ahead when, at t0, the driver of the car ahead applies his brakes and begins to slow down at a steady rate of 6.00 2, towards the posted speed limit of 50.0 mi/hr (22.4 m/s). After slowing to 50.0 mi/hr, the driver of the car ahead plans to maintain this constant speed. It takes Ralph 2.00 seconds to notice that the car ahead is slowing down, and another 1.00 second to effectively apply his brakes and begin to slow down. Assume that, once Ralph effectively applies the brakes, his car slows down at a steady rate of 6.00 m Att- 0, the Ralph's front bumper is located at X-0 and the car ahead begins to slow down at a steady 6.00 m/s 2 RALPH'S CAR 70.0 mi/hr THE CAR AHEAD 70.0 mi/hr 12.00 21. Assume, for the sake of argument, that no collision occurs. Starting at t 0, what distance does car ahead travel while slowing down to 50 mi/hr? a. 200 m b. 93.9 m c. 400 m. d. 39.8 mm e. 79.7 m 22. Assume, for the sake of argument, that no collision occurs. At the instant when Ralph effectively applies his brakes, the rear bumper of the car ahead is located at x equals a. 73.8 m b. 51.8 mm c. 56.5 m d. 68.5 m e. 85.8 m. 23. Assume, for the sake of argument, that no collision occurs. At the instant when Ralph effectively applies his brakes, the front bumper of Ralph's car is located at x equals a. 62.6 m b. 106 m c. 93.9 m. d. 74.6 mm e. 81.9 m

Answer 1

(12,0) ←一飞6.gm tz? 2) For u: 31.3m)s v 22-4m/s , v2- u2+as we hare (22-4 3 2 (a(s) 3322-42 22) This asks .co-orcinale t xear By s=ut +1at2 , sr 3h3x3-2メ6x 32-66.gm C 11 35 no brakes hemt been 93.3 m