[Smiley Face :)]

Hi ,
For the first part I got T = 167N - which is right
For the second part I am getting the Value of P to pe 6400 N which is wrong...
I resolved the force perpendicular (psin 30) and parallel to the plane (p cos 40)
Then I tried to solve it simultanoesly but it gave me 6400 N

HELP ME!!

[Imposition]

Hmmmm

I'm keep getting P=497N which I feel is wrong.

[Smiley Face :)]

(Original post by VictorDeLost)
Hmmmm

I'm keep getting P=497N which I feel is wrong.

Any idea??

[raheem94]

(Original post by Smiley Face :))
Any idea??

Is the answer P=1874N ?

[Smiley Face :)]

(Original post by raheem94)
Is the answer P=1874N ?

580N

[Smiley Face :)]

any ideas any one??

[Emissionspectra]

(Original post by Smiley Face :))
any ideas any one??

Is the answer 580N?

[4ever_drifting]

Resolving parallel and perpendicular should work - I've drawn a diagram to show the equationsI used so you can perhaps see what you're missing - these equations solve to give P as 580.16... N

Also, check your calculator isn't in radians... A mistake I've made too many times

[Aurum]

(Original post by Smiley Face :))
any ideas any one??

The least value of P occurs when friction acts up the plane. Hence,
Pcos30+0.2(175gcos30+Psin30)=175 gsin30
=> P=580.2 N as required.

[Smiley Face :)]

(Original post by Aurum)
The least value of P occurs when friction acts up the plane. Hence,
Pcos30+0.2(175gcos30+Psin30)=175 gsin30
=> P=580.2 N as required.

Ok.. so friction acts up the plane... oh yeah... stopping it from slipping down the plane!! Just realised!!

[Imposition]

(Original post by Aurum)
The least value of P occurs when friction acts up the plane. Hence,
Pcos30+0.2(175gcos30+Psin30)=175 gsin30
=> P=580.2 N as required.

I completely ignored the original weight of the sledge itself so my equation had the weight of the sledge with the two people on it as 150g.