I'm having trouble with two problems: 1. A driver is travelling at 25 m/s when she spots a sign that reads "BRIDGE OUT AHEAD". It takes her 1.0 s to react and begin braking. The car slows down at a rate of 3.0 m/s^2. Luckily, she stops 5.0 m short of the washed out bridge. a) How much time was required to stop the car once the brakes were applied? My attempt: t= 0 m/s - 25 m/s (divided by) 3.0 m/s^2 t= -8.3 t =(8.3 s) b) How far was the driver from the bridge when she first noticed the sign? My attempt: d = 0.5(V1 + V2)t d = 0.5(0 + 25) 8.3 d = 104 + 5.0 (she fell short) d = 109 m 2. A box accidently falls from the back of a truck and hits the ground with a speed of 15 m/s. it slides along the ground for a distance of 45 m before coming to rest. Determine: a) the length of time the box slides before stopping My attempt: d = 0.5(V1 + V2)t 45 = 0.5(15 + 0) t solve for t and get t = 6 c) the time it takes to slide the last 10 m I don't know this one.