I have been given these questions in a HNC engineering course, I'm rather stuck. I have many formulas but cannot work out which to use! Can anyone give me a gentle nudge in the right direction?



11) A racing car, moving with constant acceleration along a straight stretch of track, passes a fixed marker A with speed of 72 km/h. Two seconds later it passes a second fixed marker B. Given that the distance AB is 45 meters, find the acceleration of the car.

A third marker C is situated near the end of this section of track. Given that the speed of the car as it passes C is 216 km/h, find the time taken by the car to travel from A to C.



12) Assuming you are travelling along a straight level road with your car of mass 1750 kg at 30 m/s when the traffic lights change from green to amber. On seeing the amber light you apply the brakes 23 meters from the lights and just manage to stop on the line, determine:

a. the kinetic energy of the car before braking

b. the work done in bringing the car to rest

c. the force due to the brakes (friction) against which work is done

13) Explain the basic characteristics of simple harmonic motion





14) A stationary diesel generator engine has a stroke of 300mm. The motion of the piston can be assumed to be simple harmonic. Calculate the maximum linear velocity and acceleration of the piston at 3600rpm and show at what points in the oscillation they occur

You do need to show us your attempts at solving these. The first is a simple application of basic equations of motion - which one(s) have you tried? The second is basic definition of KE and equivalence of work and energy. For the third give us your attempt at a definition and we'll review it for you. And the final question requires setting up the equation for displacement as a function of time, then differentiating (twice). Again, please show is your work, and we'll help you along if you get stuck.