Describe one 'Newton's third law pair' of forces involved in the following situations. In each case, state the object that each force acts on, the type of force and the direction of the force.You throw a ball upwards into the air.

Determine the base units of:

 Pressure $\left(=\frac{\text{ force }}{\text{ area }}\right)$

Determine the base units of:

Energy $\left(=\text{Force}\times \text{Distance}\right)$

Determine the base units of:

Density $\left(=\frac{\text{ mass }}{\text{ volume }}\right)$

Use base units to prove that the following equations are homogeneous.

Pressure $=$ density $\times$ acceleration due to gravity $\times$ depth

Use base units to prove that the following equations are homogeneous.

Distance travelled $=$ initial speed $\times$ time $+\frac{1}{2}$ acceleration $\times {\text{times}}^2\left(s=ut+\frac{1}{2}a{t}^2\right)$.

 Find the area of one page of the book in ${\mathrm{cm}}^2$ and then convert your value to ${\mathrm{m}}^2$.