Density, upthrust and viscous dragEdexcel International A Level Physics: Mind map

Exam questions on Density, upthrust and viscous drag

1. A student has a solid metal cube of side 2.0 cm. Its mass, measured on a balance, is 21.6 g.
   The student has another solid object with an irregular shape that fits inside a measuring cylinder of water. Describe how the student could determine its density.2 marks
2. A solid cube of side 0.10 m and mass 0.80 kg is held fully submerged in water of density 1000 kg m⁻³. The acceleration of free fall is 9.81 m s⁻².
   The cube is released from rest. Calculate the resultant force on it at the instant of release, and state its direction.2 marks
3. A steel ball bearing of radius 2.0 mm and density 7800 kg m⁻³ is released from rest at the surface of a tall tank of glycerol. The glycerol has density 1260 kg m⁻³ and viscosity 0.95 Pa s at the temperature of the experiment. The ball falls through the glycerol and reaches a constant terminal velocity. The acceleration of free fall is 9.81 m s⁻².
   Calculate the weight of the ball and the upthrust on it when it is fully submerged.3 marks