Motion problem for constant acceleration

[chroncile]

Homework Statement

A pedestrian is running at his maximum speed of 6.0 m/s trying to catch a bus that is stopped at a traffic light. When he is at 16 m from the bus, the light changes and the bus pulls away from the pedestrian with an acceleration of 1.0 m/s².

Does the pedestrian catch the bus and, if so, how far does he have to run? (If not, what is the pedestrian's distance of the closest approach?)

Homework Equations

d = vi * t + 0.5 * a * t²

The Attempt at a Solution

I don't understand how to do it

 

[collinsmark]

Homework Equations

d = vi * t + 0.5 * a * t²

The Attempt at a Solution

I don't understand how to do it

Show us your best try. What is your equation for the displacement of the bus, from the traffic light, as a function of time t? What is your equation for the pedestrian's displacement from the traffic light as a function of time t? Is there ever a real-valued, positive time t where the displacements are equal?

Hint: there's a more general equation that you might consider using, instead of the one you quoted (and don't forget the bus and the pedestrian each have their own individual velocities and accelerations):

d = d_i + v_it + ½at²