Recent content by BlueCB

Less, would make more sense (if its to be safe). So in that case, does 250 MPa sound about right for the max working shear stress? And then: max working shear stress*cross sectional area = max working force = 250,000,000 Pa*0.000314 m^2 = 78500 N = 78.5 kN?

750 MPa = 750,000,000 Pa / 3 = 250,000,000 Pa = 250 MPa (max working stress)? or 750,000,000 Pa*3 = 2,250,000,000 Pa = 2.25 GPa (max working stress)?

I'd say unbalanced. The pivot is Ra. 25 kN and 5 kN forces are tending to turn it clockwise and the 8 kN force anti-clockwise. So a total of 30 kN clockwise force and 8 kN anti-clockwise, would tend to make one assume it's unbalanced?

Right, still a bit unsure. Just dug up some old notes related to moments; Moment of a force (Nm) = force (N)*perpendicular distance from pivot to line of action of the force (M) M = F*X Perpendicular distances = moment = force*distance from pivot Balanced object = sum of clockwise moments =...

Is there a formula for shear stress that involves the ultimate shear stress and safety factor?

Yep, 15,600 N on each front wheel (15,600*2 = 31,200)

0 = 25,000*2 + 5,000*15 -16 Rb - 8,000*2 0 = 50,000 + 75,000 - 16 Rb - 16,000 0 = 109,000 - 16 Rb 16 Rb = 109,000 Rb = 109,000 / 16 = 6812.5 N (round it to 6800) 8,000 + 25,000 + 5,000 = 38,000 N 38,000 - 6800 = 31200 N Ra = 31200 / 2 = 15600 N 38,000 - 31,200 = 6,800 N Rb therefore = 6,800 N...

And that would be "16 Rb"?

So would it just be the case of completely removing "5 Rb" from the equation if I've already accounted for it via (5,000*15)?

Would that make it "16 Rb" instead then? I thought it was 5 Rb due to the 5 kN force being 1 meter away from Rb = 5*1 = 5?

16 meters between the wheels (Ra to Rb).

Homework Statement In the diagram below, work out the reaction force in each of the wheels. Note there are two wheels that make up Ra. The Attempt at a Solution 0 = 25,000*2 + 5,000*15 -5 Rb - 8,000*2 0 = 50,000 + 75,000 - 5 Rb - 16,000 0 = 109,000 - 5 Rb 5 Rb = 109,000 Rb...

If I'm honest, not really:confused:; ultimate shear stress, safety factor, maximum working force? The terminology and what their relative units used are, is really confusing me. Although would I be right in saying that 750 MPa = 750,000,000 N/m^2? Some clarification would be very much appreciated.

So 3.14 cm^2 = 0.000314 m^2? So this would change the other answers: a) Working shear stress = Force / Area = 1,000,000 N*0.000314 m^2 = 3184713376 Pa? b) Area = pi*r^2 = pi*1 cm^2 = 3.14 cm^2 = 0.000314 m^2? c) Working force = Stress*Area = 3184713376 Pa*0.000314 m^2 = 1,000,000 N?

10,000...