Algebra & Geometry Problem, need help.

[marsgx]

Kyle decides to paint a mural on the wall in the cafeteria. He carries a 6kg can of paint up a 10m ladder which rests against the vertical wall. If the ladder is inclined at an angle of 60degrees to the ground, find the work done by Kyle in carrying both the paint, and himself, up the ladder.

 

[McPhreak]

<< find the work done by Kyle in carrying both the paint, and himself, up the ladder. >>



Don't you need the weight of Kyle?

 

[johnjohn320]

Find the work done? What the heck does that mean? How would you measure taht?

 

[Platypus]

Draw a picture..

|.......\................<10 meters
|.........\
|...........\
______<60

This makes it a 30 60 90 triangle.

Use the rule of triangles to figure out the missing sides.

What do you mean by work? How much does Kyle weigh?

 

[marsgx]

I was puzzled by the question, because the weight of the person is not given.
I also have the diagram drawn, but I don't know how to solve it.
Work = dot product = force x displacement COS@

 

[AnthraX101]

Yeah, you need the weight of the guy.

Armani

 

[marsgx]

I am thinking that the teacher wants us to make up the weight.

 

[Platypus]

UHhhhhhhhh?

What the hell is the point of that..?

Ok, following that fvcked up logic, you make up a weight in kilograms, add 6 to it for the paint, and use an algorithm

 

[lawaris]

nope it jus' means that u have to assume the weight to be ....say "m" kgs. and then get the answer in terms of m.


another way to look at this would be to take the x,y components separately and get theans.


hope that helps.


U need to know a lil' bit of calculus for that !

 

[marsgx]

But how do I find the force though?
I know the displacement, which is 10m, but how do I find the force?
The reason that I don't know how to do this question is that we haven't done this type of question before, and this question is given in a to be marked assignment. So, I really have no idea to how solve this question.......

 

[sharkeeper]

Why not make up the rest of the story...

Kyle drinks the paint when he reaches the top of the ladder.

Would this be Kyle from Hard O|C|P?

Cheers!

 

[Platypus]

<< But how do I find the force though?
I know the displacement, which is 10m, but how do I find the force?
The reason that I don't know how to do this question is that we haven't done this type of question before, and this question is given in a to be marked assignment. So, I really have no idea to how solve this question....... >>




You need an algorithim to solve the force. Perhaps its KG divided by distance or something of that sort.

 

[Heisenberg]

Work = Sine 60 degrees * 10 m * gravity (9.8 m/s^2) * (6 kg + Kyle's mass in kg). That assumes the 60 degree angle is between the ladder and the floor.

 

[Platypus]

<< Sine 60 degrees * 10 m * gravity (9.8 m/s^2) * (6 kg + Kyle's mass in kg). That assumes the 60 degree angle is between the ladder and the floor. >>



Yes it is according to the problem..

 

[Yossarian]

You are correct sir!

 

[Heisenberg]

<< Yes it is according to the problem.. >>



Ok, then what I have above should be right. I missed the 'to the ground' part when I read it the first time.

 

[marsgx]

<< << Sine 60 degrees * 10 m * gravity (9.8 m/s^2) * (6 kg + Kyle's mass in kg). That assumes the 60 degree angle is between the ladder and the floor. >> >>



I don't think that is right. First of all, that should be a Cosin rather than a Sin. Secondly, 10m is the displacement, you don't multiple that by the gravity. The one that you multiple by the gravity is the mass.

 

[Heisenberg]

<< I don't think that is right. First of all, that should be a Cosin rather than a Sin. Secondly, 10m is the displacement, you don't multiple that by the gravity. The one that you multiple by the gravity is the mass. >>



Work due to gravity is equal to the mass times gravity times the vertical displacement. The vertical displacement in this case is the sine of the angle times the hypotenuse (the 10m ladder). Sine = opposite/hypotenuse correct? The mass is then the 6 kg can plus whatever the guy's mass is.

 

[marsgx]

Oh yes, you were finding the vertical displacement, sorry about that.
I was talking about different thing... haha...
I was actually talking about the forumla of the dot product.... opssy

 

[PullMyFinger]

Yeah, but is he carrying the paint in his left or right hand?

J/K, Heisenberg is absolutely correct, work = force * distance.

 

[Bulldozer]

BTW, the result is in Newton*meters. 1 newton*meter = 1 Joule