CIE iGCSE Co-Ordinated Science P1.5.3 Centre of gravity Exam Style Questions Paper 2
Question
A plant was placed horizontally in complete darkness.
The diagram shows how the plant had grown after one week.
Which response has the shoot made?
(A) gravitropism away from gravity
(B) gravitropism towards gravity
(C) phototropism away from light
(D) phototropism towards light
▶️Answer/Explanation
Ans: A
Question
A uniform beam of length 20 cm is balanced on a pivot at its centre.
A 20 N load is placed at one end of the beam and a 30 N load is placed at the other end.
A 25 N load is also placed on the beam to balance it.
How far from the pivot is the 25 N load placed?
(A) 4.0 cm
(B) 5.0 cm
(C) 8.0 cm
(D) 10 cm
▶️Answer/Explanation
Ans: A
Question
A person uses a bar that is 3.0 m long to lift a rock of weight 900 N off the ground. There is a pivot under the bar at 0.50 m from the rock.
The person pushes vertically downwards on the other end of the bar from the rock, as shown.
Ignore the weight of the bar.
What is the minimum force needed to lift the rock off the ground?
(A) 150N
(B) 180N
(C) 4500N
(D) 5400N
▶️Answer/Explanation
Ans : B
Question
Three objects X, Y and Z are at rest on a table. The centre of mass of each object is labelled M.
What is the order of stability of these three objects, from most stable to least stable?
A X → Y → Z
B Y → Z → X
C X → Z → Y
D Z → Y → X
▶️Answer/Explanation
Answer: D
Explanation: The stability of an object depends on the position of its centre of mass. The lower the centre of mass, the more stable the object. Object Z has the lowest centre of mass, making it the most stable, followed by Y and then X.