So, I understand that there is a force acting on the plane, vertically down from the 8kg weight; which is 8g.
I also then know that the force acting perpendicular to the weight is 8gsin30 and the force acting against the friction is 8gcos30.
However, my paper says that Pcos30 = F + 8sin30...
I would understand if it said P = F + 8sin30, but where does the Pcos30 come from?
Forces in Equilibrium (horizontal) on an incline?
回答 (3)
2018-03-03 1:24 am
P would equal F + 8sin(30) if the force of P was parallel to F...but its not but rather Pcos(30)
2018-03-03 3:53 am
The weight of the block has a component that is parallel and perpendicular to the plane.
Weight = 8 * 9.8 = 78.4 N
Parallel = 78.4 * sin 30 = 39.2 N
Perpendicular = 78.4 * cos 30
The force P has a component that is parallel and perpendicular to the plane.
Parallel = P * cos 30
Perpendicular = P * sin 30
Since we do not have a coefficient of friction, we can assume that there is no friction. To prevent the block from accelerating, the sum of the parallel components must be 0 N
Net force parallel = 39.2 – P * cos 30
39.2 – P * cos 30 = 0
P = 39.2 ÷ cos 30
This is approximately 45 N. I hope this is helpful for you.
Weight = 8 * 9.8 = 78.4 N
Parallel = 78.4 * sin 30 = 39.2 N
Perpendicular = 78.4 * cos 30
The force P has a component that is parallel and perpendicular to the plane.
Parallel = P * cos 30
Perpendicular = P * sin 30
Since we do not have a coefficient of friction, we can assume that there is no friction. To prevent the block from accelerating, the sum of the parallel components must be 0 N
Net force parallel = 39.2 – P * cos 30
39.2 – P * cos 30 = 0
P = 39.2 ÷ cos 30
This is approximately 45 N. I hope this is helpful for you.
2018-03-03 2:20 am
Forces in equilibrium so no friction applies as the box does not move (unless forces unbalance and overcome static friction)
box = 8g sin 30 (gravity along plane to left)
F1 = P cos 30 (along plane to right)
F2 = F (along plane to left
P cos 30 = 8g sin 30 + F
Vertically (perpendicular to plane)
N (normal from incline) = P sin 30 + 8g cos 30
box = 8g sin 30 (gravity along plane to left)
F1 = P cos 30 (along plane to right)
F2 = F (along plane to left
P cos 30 = 8g sin 30 + F
Vertically (perpendicular to plane)
N (normal from incline) = P sin 30 + 8g cos 30
收錄日期: 2021-04-24 00:56:51
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