MJ20 P52 Q2 Viscosity of Liquid

 9702/52/M/J/20: A student investigates how the viscous force in a liquid varies with temperature.
The student releases a ball from the surface of the liquid in a container. The ball falls as shown in
Fig. 2.1. The student determines the speed of the ball between P and Q and measures the thermodynamic
temperature T of the liquid.

Viscosity is a term used to describe the viscous forces acting in a liquid. Viscosity has the unit
pascal second (Pas). The viscosity η of the liquid is calculated from the speed of the ball. The experiment is repeated for the same liquid at different temperatures. It is suggested that η and T are related by the equation 

\( \eta = He^{\frac{E}{kT}}\)

where E and H are constants and k is the Boltzmann constant.

May/June 2020 Paper 5 Variant 2 Questions 2 data analysis.

 

MJ20 P51 Q2 Discharging Capacitor

9702/51/M/J/20: A student investigates the discharge of a capacitor through a resistor using the circuit shown in Fig. 2.1. The student initially closes the switch and charges the capacitor. The switch is then opened and a stop-watch is started. The capacitor discharges through the resistor. At time t the potential
difference V across the capacitor is measured.

It is suggested that V and t are related by the equation where Q0 is the charge of the fully charged capacitor, C is the capacitance of the capacitor and R is the resistance of the resistor.

 May/June 2020 Paper 51 Question 2.