Year 12s: what will be the first way you research your future options? >>

M1 question

I dont know how to do question 8(b). I guess I need to find the reaction force first. But i dont know how to find it, please help

Reply 1

Notnek

Original post by alesha98

I dont know how to do question 8(b). I guess I need to find the reaction force first. But i dont know how to find it, please help

Since there is no vertical acceleration, the reaction is equal to the weight of the particle.

Reply 2

alesha98

Original post by notnek

Since there is no vertical acceleration, the reaction is equal to the weight of the particle.

So for Q, the reaction force is 3g.
For P, the reaction force is 2g?

Reply 3

Notnek

Original post by alesha98

So for Q, the reaction force is 3g.
For P, the reaction force is 2g?

That's correct.

Reply 4

alesha98

Original post by notnek

That's correct.

Thanks, one more question. When doing this type of question, should i consider the particles as a whole single system, or two separate particles?

Reply 5

Notnek

Original post by alesha98

Thanks, one more question. When doing this type of question, should i consider the particles as a whole single system, or two separate particles?

The particles are moving in the same straight line so it's okay to consider the whole system. And you can also consider the particles separately.

For a question like this you often may need to consider the whole system for one part of the question and a single particle for another.

Have a go at the question and post your working if you get stuck.