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# Need help on M1 Question - Working attached watch

1. I'm currently doing this question, and can't seem to get the right answer. I have seen the mark scheme, but the method used is not something I would generally attempt first. I would resolve upwards to eliminate X to find R, in order to calculate the F value - to then use F=ma to find X. I have attached my working and would really appreciate it if someone could spot where I'm going wrong in my method, as I've attempted this many times with no luck of reaching the correct answer of X = 45N.

Thanks
Attachment 539451539455
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2. (Original post by Louiseelg0rt)
I'm currently doing this question, and can't seem to get the right answer. I have seen the mark scheme, but the method used is not something I would generally attempt first. I would resolve upwards to eliminate X to find R, in order to calculate the F value - to then use F=ma to find X. I have attached my working and would really appreciate it if someone could spot where I'm going wrong in my method, as I've attempted this many times with no luck of reaching the correct answer of X = 45N.

Thanks
Attachment 539451539455
P is accelerating up the plane. The acceleration has a horizontal component and a vertical component.

Resolving vertically, upward force does not equal downwards force.

Edit: Not checked all of it.
3. (Original post by Louiseelg0rt)
I'm currently doing this question, and can't seem to get the right answer. I have seen the mark scheme, but the method used is not something I would generally attempt first. I would resolve upwards to eliminate X to find R, in order to calculate the F value - to then use F=ma to find X. I have attached my working and would really appreciate it if someone could spot where I'm going wrong in my method, as I've attempted this many times with no luck of reaching the correct answer of X = 45N.
Resolving parallel to the slope is perfect, good job on that.

Unfortuantely, you need to resolve perpendicular to the slope to get another equation to find friction and reaction. If you resolve vertically, it's not in vertical equilibrium so your equation doesn't hold.

Edit: Ninja'd.
4. Zacken ghostwalker
Thank you! I was treating this like a standard statics problem, I see why it's wrong now.

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