Mathematics 9709 · AS & A Level · Newton's laws of motion
Newton's laws of motion — practice question
A particle is launched from point P with initial speed $u\,\text{m s}^{-1}$ up the line of greatest slope $PQR$ on a rough inclined plane. The distances $PQ$ and $QR$ are each $0.8\,\text{m}$. The particle takes $0.6\,\text{s}$ to move from $P$ to $Q$ and $1\,\text{s}$ to move from $Q$ to $R$.
(i)[6]
Demonstrate that the particle’s deceleration is $\frac{2}{3}\,\text{m s}^{-2}$ and then determine $u$, with the answer given as an exact fraction.
(ii)[4]
The plane is inclined at $3^{\circ}$ to the horizontal; determine the coefficient of friction between the particle and the plane.
Worked solution & mark scheme
This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Applying constant-acceleration equations, for example $s = ut + \tfrac12at^2$” …