EME1501 Assignment 3 2026 - Due 12 June 2026 (Distinction)

EME1501
ASSIGNMENT 3 2026
DUE: 12 JUNE 2026 (MEMO)

, EME1501 ASSIGNMENT 3 MEMO 2026
DUE 12 JUNE 2026


Question 1

Determine the minimum force P and its location d so that the mass of 1 slug bar shown in the

Figure below is in equilibrium with impending motion downward at the lower end? (10)




Walker, M (2014) lie Me ani or En ineerin e nolo , t e ear on ( a ter 1,2, ,4,5,7, , )


For impending motion down the slope:
ΣFx = 0 ⇒ −P − μW cos θ + W sin θ = 0

P = W (sin θ − μ cos θ)

W = 32.2 lb, sin 40∘ = 0.6428, cos 40∘ = 0.7660

P = 32.2 (0.6428 − 0.4 × 0.7660) = 32.2 × 0.3364 = 10.83 lb

For tipping about lower end (moments):

ΣMlower = 0 ⇒ P ⋅ d = W sin θ × L

W sin θ × L 32.2 × 0.6428 × 20
d= = = 38.2 in.
P 10.83
Alternatively, using the formula from the memo:

L tan θ 20 × 0.8391
d= = = 38.2 in.
tan θ − μ 0.8391 − 0.4


P = 10.8 lb, d = 38.2 in.