Equilibrium and Centre of Gravity Questions and Answers - Physics Form 2 Topical Revision

Questions

1. The figure below shows two identical trolleys with loads A and B. The loads are identical in shape and size.
   Given that the density of A is greater than that of B, explain why the trolley in (ii) is more stable.
   
2. The figure below shows a solid cylinder standing on a horizontal surface. The cylinder is in stable equilibrium.
   
   In the horizontal space provided, sketch the cylinders in neutral equilibrium
3. State two factors that determine the stability of a vehicle
4. State the necessary conditions for equilibrium of body which is acted upon by a number of forces
5. State the modification introduced in the modern buses so as to enhance stability
6. The figure below show a beaker placed on a bench. A block of ice is placed in the beaker as shown.
   
   State and explain the changes in the stability of the beaker when the ice melts.
7. The figure below shows beaker containing water at 00. The beaker is placed on a bench.
   
   State and explain the changes in stability of beaker when water freezes

Answers

1. The c.o.g is lower since the heavier base the lower the c.o.g.
2. Cylinder should be lying down.
   
3. - Position of centre of gravity
   - Width of its base i.e. length of axle
4.  
   1. The sum of upward forces should be equal to the sum of downward forces.
   2. The sum of clockwise moments should be equal to the sum of anticlockwise moments.
5. • Luggage compartments are located on the lower part of the bus.
   • Engine is located as low as possible.
   • Floor of the bus is carpeted by a heavy gauge metallic material.
   • Light material is used for making the upper part of the bus.
6. When the ice melts, water contracts hence centre of gravity lower. The beaker becomes more stable 
7. -Beaker becomes less stable.
   -Water expands on freezing raising the centre of gravity of the beaker.