Question

g You are following 25 m behind another car on the highway while talking on the cell phone. Both you and the other car initially have a constant speed of 110 km/hr. You being to argue with the person on the phone and become distracted from the road for 2 seconds. At the beginning of that two seconds, the other car sees something in the road ahead and begins to break hard, at 5 m/s2 . (a) How far apart are the two cars when your attention returns to the road

Answer 1

Δx = 10 m

Step-by-step explanation:

For this problem we can calculate the distance traveled by each car in the time of 2 s

let's reduce the speed to the SI system

v = 110 km / h (1000m / 1 km) (1 h / 3600 s) = 30.556 m / s

Cart 1

this car has constant speed

v = x₁ / t

x₁ = v t

x₁ = 30,556 2

x₁ = 61.11 m

This car is that of the person with the cell phone

Cart 2

this car has an acceleration of a = 5 m / s²

x₂ = v₀ t - ½ a t²

x₂ = 30,556 2 - ½ 5 2²

x₂ = 51,112 m

The difference in distance between the two vehicles is

Δx = x₁ - x₂

Δx = 61.11 - 51.11

Δx = 10 m