Physics 9702 · AS & A Level · SI units

SI units — practice question

(a)[3]

Show that the SI base units for power are $\text{kg m}^2 \text{s}^{-3}$.

(b)[4]

Determine the SI base units of $C$ for the thermal-energy flow rate $\frac{Q}{t}$ in a material, where $\frac{Q}{t} = \frac{CAT}{x}$, $A$ is the cross-sectional area of the material, $T$ is the temperature difference across the thickness of the material, $x$ is the thickness of the material, and $C$ is a constant.

(main)[2]

Use the data from Fig. 3.2 to show that the box's acceleration is $2.6\,\text{m s}^{-2}$.

Worked solution & mark scheme

This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: Power is energy per unit time, or work done per unit time

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