1.Easy
The bell crank shown turns about the pin O. A vertical force of 300 N acts at A, 180 mm from O, and is balanced by a horizontal force Q at B, 50 mm above O. Find Q.
F = 300 NOA = 180 mmOB = 50 mm
Q = N
Frames & machines worksheet with answers
2.Easy
The bell crank shown turns about the pin O. A vertical force of 250 N acts at A, 240 mm from O, and is balanced by a horizontal force Q at B, 120 mm above O. Find Q.
F = 250 NOA = 240 mmOB = 120 mm
Q = N
3.Medium
The A-frame shown stands on a pin at A and a roller at B, 3 m apart. The legs meet at the pin C, 2 m high, and the horizontal tie DE is 0.6 m above the ground. A load of 2 kN acts at C. Find the magnitude of the force C that the pin C exerts on leg BC.
P = 2 kNAB = 3 mheight of C = 2 mheight of DE = 0.6 m
C = kN
4.Medium
A horizontal beam AB is pinned to a wall at A and propped by the strut CD, pinned to the wall at C, 0.8 m below A. A load of 3 kN hangs at B. Neglect the weights. Find the magnitude of the pin force A on the beam at A.
P = 3 kNAD = 0.5 mAB = 1.5 mAC = 0.8 m
A = kN
5.Hard
The A-frame shown stands on a pin at A and a roller at B, 3 m apart. The legs meet at the pin C, 2.5 m high, and are tied by the horizontal bar DE at 1 m. A horizontal force of 5 kN to the right acts at C. Find the tension T in the tie.
P = 5 kNAB = 3 mheight of C = 2.5 mheight of DE = 1 m
T = kN
6.Hard
A uniform horizontal boom AB of weight 0.5 kN is pinned to a wall at A and held by a cable from its end B to the point C on the wall, 2.5 m above A. A load of 2 kN hangs at B. Find the tension T in the cable.
W = 2 kNWb = 0.5 kNAB = 4 mAC = 2.5 m
T = kN
Answer key
- 1. Q = 1080 N
- 2. Q = 500 N
- 3. C = 1.466 kN
- 4. A = 8.224 kN
- 5. T = 4.167 kN
- 6. T = 4.245 kN
Full step-by-step solutions: practise this topic on examproblems.com.