(i)[2]
Show that $v\frac{dv}{dx} = 1.2x^2 + 8$ using the information given.
(ii)[3]
Find $B$'s velocity when $x = 1.5$.
(iii)[2]
Find the size of this extra force and state the direction of its action.
Mathematics 9709 · AS & A Level · Representation of data
Representation of data — practice question
A small block $B$ of mass $0.25\,\text{kg}$ is let go from rest at point $O$ on a smooth horizontal surface. Once released, the velocity of $B$ is $v\,\text{m s}^{-1}$ when its displacement from $O$ is $x\,\text{m}$. The force on $B$ has magnitude $(2 + 0.3x^2)\,\text{N}$ and acts horizontally away from $O$.