Practise Edexcel A-Level Physics upthrust and displaced fluid through floating equilibrium, hydrometers, balloons, submarines and weight-of-fluid calculations.
A student determined the viscosity of a liquid using the falling-ball method.
When the ball is falling at terminal velocity the following equation applies
The density of the liquid was known.
The student used a balance and a digital calliper to make measurements on the ball.
Describe how the student could use her measurements to calculate a value for the drag force acting on the ball.
(Use balance to measure) mass and multiply mass by g to determine weight
Or
Use the balance set to read newtons to determine weight (of ball)
Measure the diameter (of the ball) (with the calliper) to determine volume
Identify upthrust with weight of fluid displaced
Calculate the weight of fluid displaced by multiplying the volume of the ball by the density of the liquid and g