Determine the magnitude and direction of smallest force

AI Thread Summary
To determine the smallest force F needed to move the oil drum with a resultant force of 500 N, the equations for the summation of forces in both x and y directions are essential. The user attempted to apply the Pythagorean theorem to find the resultant but encountered two unknowns: the magnitude F and its direction p. A suggestion was made to combine the two given forces into a single net force to find an efficient direction for F. The discussion emphasizes that the force should ideally align with the direction of the resultant for maximum efficiency. Understanding these principles is crucial for solving the problem effectively.
blackandyello
Messages
9
Reaction score
0

Homework Statement



To move the oil drum, the resultant of the three forces shown must have
a magnitude of 500 N. Determine the magnitude and direction of the smallest
force F that would cause the drum to move.

here is the figure: http://screensnapr.com/e/yliMVN.png

Homework Equations



summation of x forces = 0 - 300 * cos25 + F cos (p)
summation of y forces = 250 - 300 * sin 25 + F sin (p)

The Attempt at a Solution



i tried using those 2 equations and put it in

R ^2 = x ^2 + y ^2 (phytagorean theorem for resultant)

but i ended with 2 variables missing which is F (magnitude) and p(direction). Any insights? Thanks
 
Last edited by a moderator:
Physics news on Phys.org
Take the two forces given and combine them to give a single net force, draw that in and you should be able to find a direction which uses your force the most efficiently :)
 
when we say most efficiently? u pertain that it has to be in the same direction as the resultant?
 
yep, you got it.
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top