How Does Mass Affect Acceleration and Deceleration in a Lorry?

[RoryOBigtool]

Homework Statement

Ok I have been given an assignment and asked to answer questions about a lorry loaded and unloaded. the Text is as follows:
An unloaded lorry of mass M kg accelerates from rest and reaches a velocity of 30mph in 10 seconds. It then travels at constant velocity for half a minute before the driver applies the brakes and brings the vehicle to rest over a distance of D m.
The lorry is then loaded with 800 kg of building materials that need to be transported over a total distance of 0.6 km. After loading, the lorry accelerates over a distance of 80m to attain a velocity of 30mph again. The vehicle subsequently maintains constant velocity before decelerating to rest at a rate of R m/s2.

M=2300KG D = 70m R = 1.5m/s^2

Homework Equations

The questions exactly
Find for the unloaded lorry:

i) the force required to accelerate the vehicle, and the retarding force necessary to bring it to rest;
ii) the total time and the total distance traveled during this period.

Find for the loaded lorry :

i) the force required to accelerate the vehicle and the retarding force necessary to bring it
to rest;

ii) the total time taken during this period and the distance traveled at constant velocity.

c) Calculate the % change in the momentum of the lorry from loaded to unloaded, whilst traveling at the specified constant velocities.

d) Draw the ‘velocity-time’ graph of the motion of the lorry in its unloaded and loaded states, indicating clearly salient points and values.

The Attempt at a Solution

I tried using V^2 = U^2 +2as , V=S/t and general thinking but I am 100% sure that I am incorect. i got answers like 0.65 m/s^2 which seemed possible but it is half the acceleration than when the lorry was unloaded, i think half is too little if only 800KG was added. i also got stupid answers like 15.67 m/s^2

can some one help me

 

[ideasrule]

Read your own post again and you'll see why I can't understand it at all. What information is provided about the unloaded lorry? What's the actual question? Why does the 0.6 km matter?

 

[PhanthomJay]

I believe you left out some info regarding the unloaded lorry, like its acceleration, speed, etc. And you left out the question as well. Please re-write this problem in its entirety.

 

[RoryOBigtool]

hey i edited the original message. i think i have got the full way to B) correctly. I need B to continue though, so you can see my de lima. I usually know what I am talking about when it comes to physics but this has really stumped me! any help is a positive result :)

Also does anyone know the value of e in the equation of electric field strength ( E = 1 / 4(pie) eo er x Q1Q2/r^2 )?