Record of Travel Problem Guidance

[gasapple]

Greetings,

I was wondering if someone could provide guidance on the following problem? I'd like to arrive at the correct answer(s) and know how I obtained it!

A record of travel along a straight path is as follows:
1. From rest, with a constant accel. of 2.77 m/s^2 for 15.0 s
2. Maintain a const. vel for next 2.05 min
3. Apply neg accel. of -9.47 m/s^2 for 4.39 s

What was total displacement?
What were the average speeds for legs 1, 2, 3 of trip as well as the complete trip?

Any help/guidance would be appreciated - mainly the approach and why it is so. I have a feeling it's the multiple steps that are discouraging...

Thanks in advance!

 

[Doc Al]

Treat each segment separately. Keep track of the distance traveled in each segment, and the speeds at the beginning and end of each segment.

You'll need to be able to find the distance traveled and speed for uniformly accelerated and constant velocity motion. You may find these kinematic equations helpful (but it's up to you to figure out how to use them):
$$x_f = x_i + v_i t + 0.5 a t^2$$
$$v_f = v_i + a t$$

 

[gasapple]

Thanks for the direction. I'll see what I can come up with!
Cheers