An open-top tour bus has a lower deck and an upper deck.
Passengers on the upper deck are instructed to remain seated while the bus is in motion. If passengers stand up on the upper deck, the bus becomes less stable.
Why does standing make the bus less stable?
The total weight of the bus and passengers increases when they stand.
The pressure on the upper deck floor decreases.
The centre of mass of the bus and passengers is higher.
The friction between the wheels and the road decreases.
19 exam-style questions on CIE IGCSE Physics 1.5.3 Centre of gravity and stability. Each one has a worked solution and a mark scheme showing where the marks go.