On a one lane road, a person driving a car at v₁ = 68 mi/h suddenly notices a truck d = 1.5 mi in front of him. That truck is moving in the same direction at v₂ = 45 mi/h. In order to avoid a collision, the person has to reduce the speed of his car to v₂ during time interval t. The smallest magnitude of acceleration required for the car to avoid a collision is a. During this problem, assume the direction of motion of the car is the positive direction.

Enter an expression for x₁ in terms of v₁, v₂, and t

Calculate the value of t in hours.

Calculate the value of a in meters per second squared.