1. 1
   A haulage company loads heavy cargo into a delivery truck and is concerned about the truck's stability while cornering.

   (a)

   A haulage company loads cargo into a delivery truck. What is meant by the centre of gravity of the loaded truck?

   [1 mark]

   • AThe single point through which the whole weight of the truck may be considered to act
   • BThe exact geometric centre of the truck's outer shape
   • CThe point where the truck's engine is located
   • DThe lowest point of the truck's wheels

   (b)

   The cargo is instead stacked much higher up inside the truck, rather than close to the floor. What effect does this have on the truck's stability?

   [1 mark]

   • AIt raises the centre of gravity, making the truck less stable
   • BIt lowers the centre of gravity, making the truck more stable
   • CIt has no effect on the truck's stability
   • DIt reduces the truck's overall weight

   (c)

   Explain, in terms of centre of gravity, why loading heavy cargo as low down as possible in the truck improves its stability while cornering.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A furniture designer compares two table lamp designs of the same weight: one with a narrow base and a tall, top-heavy body, and one with a wide base and most of its mass concentrated low down.

   (a)

   A furniture designer compares two table lamp designs: one with a narrow base and a tall, top-heavy body, and one with a wide base and most of its mass low down. Which design will be more stable?

   [1 mark]

   • AThe wide-based lamp with a low centre of gravity
   • BThe narrow-based, top-heavy lamp
   • CBoth designs are equally stable
   • DStability does not depend on the base or centre of gravity

   (b)

   The narrow-based lamp is tilted slightly. What happens if the vertical line through its centre of gravity falls outside its base?

   [1 mark]

   • AThe lamp topples over
   • BThe lamp returns to its upright position
   • CThe lamp's weight becomes zero
   • DThe lamp's centre of gravity moves to the floor

   (c)

   State the condition, in terms of the centre of gravity and the base, for an object such as the table lamp to remain stable rather than toppling over when tilted.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A physics class carries out an experiment to determine the centre of gravity of an irregularly shaped plane lamina (a flat sheet of card), using a pin, a cork board and a plumb line.

   (a)

   State what is meant by the centre of gravity of an object, and describe how a pin, a cork board and a plumb line would be used as the first stage of an experiment to find the centre of gravity of an irregularly shaped plane lamina (a flat sheet of card).

   [3 marks]

   (b)

   Describe the remaining steps of the experiment needed to find the exact position of the centre of gravity of the lamina, and explain why this method correctly locates the centre of gravity.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A bus manufacturer carries out tilt tests on a new double-decker bus design to check its stability, while a separate engineering team designs the outriggers for a mobile crane.

   (a)

   Describe, in full, an experiment to determine the position of the centre of gravity of an irregularly shaped plane lamina, using a pin, a cork board and a plumb line, explaining clearly how the final position is obtained from your measurements.

   [6 marks]

   (b)

   Explain, qualitatively, how the position of the centre of gravity and the width of the base affect the stability of a double-decker bus, and describe two design features engineers could use to make the bus less likely to topple over while cornering.

   [6 marks]

   Total for question 4: 12 marks

End of questions