CIE iGCSE Co-Ordinated Science P1.5.2 Turning effect of forces Exam Style Questions Paper 2
Question
A uniform metre rule rests on a pivot at the 50 cm mark. A load L is placed at the 30 cm mark and a load of 6.0 N is placed at the 80 cm mark. The arrangement is balanced.

What is the weight of load L?
A. 6.0 N
B. 9.0 N
C. 16 N
D. 24 N
▶️ Answer/Explanation
At equilibrium, clockwise moment = anticlockwise moment: \(L \times 20 = 6.0 \times 30\).
Solving: \(L = \frac{180}{20} = 9.0\text{ N}\).
✅ Answer: (B)
Question
The diagram shows a crane supporting a load of 6000 N. The horizontal distance between the load and the pivot is x.
The load is balanced about the pivot by a concrete block of mass 10 000 kg. The horizontal distance of the concrete block from the pivot is 2.0 m.
Gravitational field strength g is 10 N/kg.

What is the distance of x?
A. 1.2 m
B. 3.3 m
C. 12 m
D. 33 m
▶️ Answer/Explanation
At balance, the clockwise moment equals the anticlockwise moment: \(6000 \times x = 100\,000 \times 2.0\).
Solving gives \(x = \frac{200\,000}{6000} \approx 33\) m.
✅ Answer: (D)
Question
The diagram shows a triangular sheet of metal with sides of length \(50\text{ cm}\), \(40\text{ cm}\) and \(30\text{ cm}\). The sheet is free to move about a pivot at the top corner, as shown.

A cord is attached to the bottom left corner of the sheet and pulled with a horizontal force of \(5.0\text{ N}\) to the left.
What is the moment of the \(5.0\text{ N}\) force about the pivot?
A. \(150\text{ Ncm}\)
B. \(200\text{ Ncm}\)
C. \(250\text{ Ncm}\)
D. \(600\text{ Ncm}\)
▶️ Answer/Explanation
\(\text{Moment} = F \times d = 5.0 \times 40 = 200\text{ Ncm}\).
✅ Answer: (B)
Question
A uniform beam has a mass of 12 kg and a length of 4.0 m. The beam rests on horizontal ground. One end of the beam is now raised from the ground by a vertical force F. The other end of the beam remains in contact with the ground and acts as a pivot.

The gravitational field strength g is 10 N/kg.
What is the value of F?
A. 6.0 N
B. 24 N
C. 60 N
D. 240 N
▶️ Answer/Explanation
Taking moments about the pivot: \(F \times 4.0 = 120 \times 2.0\), so \(F = \frac{240}{4.0} = 60\text{ N}\).
✅ Answer: (C)
Question
The diagrams show uniform metre rulers each pivoted at the 50 cm mark. Different weights are placed on the rulers at different distances from the 0 cm end.
Which ruler rotates in a clockwise direction?

▶️ Answer/Explanation
✅ Answer: (A)
