M1 maths q

Lets have a specific question. What have you tried.

Reply 2

OP

Original post by nerak99

Lets have a specific question. What have you tried.

I tried to find out the force opposite moving down the plane but got a weird answer and wasnt sure how to find acceleration? do i use suvat and which equation? i had no clue how to show that the parcel come to rest do i use suvat again or?

Reply 3

Original post by sophiahello

I tried to find out the force opposite moving down the plane but got a weird answer and wasnt sure how to find acceleration? do i use suvat and which equation? i had no clue how to show that the parcel come to rest do i use suvat again or?

I always find that drawing a diagram of forces helps. Include the weight, reaction force, friction and tension. Equate forces acting parallel and perpendicular to the slope, and don't forget the life saving equation F=ma.

Reply 4

OP

Original post by aadil10

I always find that drawing a diagram of forces helps. Include the weight, reaction force, friction and tension. Equate forces acting parallel and perpendicular to the slope, and don't forget the life saving equation F=ma.

i was given a diagram :smile:

i just dont know how to find the downward force acting down the slope

Reply 5

Original post by sophiahello

i was given a diagram :smile:

i just dont know how to find the downward force acting down the slope

Out of the 4 forces I mentioned, which ones act parallel to the slope?

Reply 6

OP

Original post by aadil10

Out of the 4 forces I mentioned, which ones act parallel to the slope?

friction is the only one i think

Reply 7

If there is force or energy involved then it is not suvat. suvat says nothing about Forces. Once you have a you can then use it in suvat provided a is constant.

This is Forces and F=ma

The diagram is missing but from my reading of the Q. The normal reaction is 2g Cos 30 - 24 Cos 60 and hence the friction is 0.4 X (2g Cos 30-12)=2

Up the slope is component of 24 N. Down the slope you have friction and weight. Use F=ma to get a

Resolving parallel to slope you have 24 Cos 30 (force up slope) - (the component of weight down the slope (2g Sin 30 or 2g Cos 60) plus the friction)=ma

24cos 30 - (2g X 0.5 + 2) = 2a. Solve that for a. I get 4.49

Having got a sorted out, how do you get on with the rest.

When the rope breaks the 24N component goes but everything else is the same.

(edited 7 years ago)

Reply 8

Original post by sophiahello

friction is the only one i think

Friction is correct but it's not the only answer. Remember, forces always come in pairs. Draw arrows showing the direction each force is acting. Any that aren't perpendicular to the slope are still contributing to the parallel.

Reply 9

Original post by nerak99

If there is force or energy involved then it is not suvat.

This is Forces and F=ma

The diagram is missing but from my reading of the Q. The normal reaction is 2g Cos 30 and hence the friction is 0.4 X 2g Cos 30

Up the slope is component of 24 N. Down the slope you have friction and weight. Use F=ma to get a

Resolving parallel to slope you have 24 Cos 30 (force up slope) - (the component of weight down the slope (2g Sin 30 or 2g Cos 60) plus the friction)=ma

24cos 30 - (2g X 0.5 + 0.4 X 2g Cos 30) = 2a. Solve that for a. I get 2.089

Having got a sorted out, how do you get on with the rest

telling someone the answer doesn't really help them to understand how to solve the problem.

Reply 10

Original post by aadil10

telling someone the answer doesn't really help them to understand how to solve the problem.

Starting them off does when they are stuck. You don't have to say anything if you have nothing constructive to say and if you have an issue then DM me.

Reply 11

OP

Original post by aadil10

Friction is correct but it's not the only answer. Remember, forces always come in pairs. Draw arrows showing the direction each force is acting. Any that aren't perpendicular to the slope are still contributing to the parallel.

so also the one that is F but im not sure what its called just the force?

Reply 12

Original post by sophiahello

so also the one that is F but im not sure what its called just the force?

Saying "Forces always come in pairs" is (a) Not true and (b) not really helpful.

Reply 13