Hey there!
Gonna try guiding you instead of giving the answers to you straight up, since you need to going through these thought processes in an exam
6. a) Try using the equation W=Fs using the information given!
b) Remember that the work done is equal to the change in energy (this isn't technically correct in the real world, but it's a simplification we're using).
c) Equate the value from a) using E=0.5mv^2
d) Self explanatory, it's given in the question
e) Given acceleration, displacement, and initial velocity, try using one of the kinematic equations (SUVAT) to relate these three quantities to time!
7. a) Given that KE=0.5mv^2, calculate the initial and final kinetic energy and find the difference
b) Equate this value to work done to find the force acting over a distance that slows it down (W=Fs)
c) It's basically just a frictional force acting against the tires in the opposite direction to motion
d) similar to d) and e) from above
If you need any further help/full working, glad to provide it
Hope this helps!