I was wondering if anyone could give me some hints as to how I am supposed to do part 3 of this question.

2.Calculate the horizontal component of the acceleration of the block.

Express your answer in terms of

,

,

, and constant

.

3.Calculate the vertical component of the acceleration of the block.Express your answer in terms of

,

,

, and constant

.

Note I have done part 2 and correctly got the answer ( I have added it to my post as I think it may be needed for part 3). The answer to part 2 is:

Anyway for part 3 I keep getting the wrong answer, could someone please explain how to do it?

By the way the answer you should get is: