Question 1 is perfect.

Question 2 is good for full marks but you should simplify e.g.

or even better,

.

Question 3 is perfect.

Question 4… you are not fully communicating to me and this is leading to errors. Part i is looking for

.

By not doing that you ended up doing:

,

which is incorrect. Finally, although it wouldn’t cost you marks, you should round the error approximation to one significant figure (so ) and have the same precision (one decimal place) with your best guess of ().

Question 5 went wrong. Start with

.

You are not going anywhere without this. Remember the rate of change of (with respect to time) is , and the units of are the units of divided by the units of :

,

where here means “the units of “.

Regards,

J.P.

Can you correct these answers for the questions from the sample exam in the book please.

Thank you,

Alex.