| Exam Board | WJEC |
|---|---|
| Module | Unit 4 (Unit 4) |
| Year | 2018 |
| Session | June |
| Marks | 9 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Motion on a slope |
| Type | Motion with applied force on slope |
| Difficulty | Moderate -0.3 This is a standard mechanics problem involving forces on an inclined plane with friction. Part (a) requires resolving forces, calculating friction, and applying F=ma - routine A-level mechanics. Part (b) is even simpler, just comparing forces to determine motion. The calculations are straightforward with no conceptual surprises, making it slightly easier than average but still requiring proper method. |
| Spec | 3.03t Coefficient of friction: F <= mu*R model3.03v Motion on rough surface: including inclined planes |
An object of mass 60 kg is on a rough plane inclined at an angle of 20° to the horizontal. The coefficient of friction between the object and the plane is $0 \cdot 3$. Initially, the object is held at rest. A force which is parallel to the plane and of magnitude $T$ N is applied to the object in an upward direction along the line of greatest slope. The object is then released.
\begin{enumerate}[label=(\alph*)]
\item Given that $T = 15$, calculate the acceleration of the object down the plane. [6]
\item Given that $T = 350$, determine whether or not the object moves up the plane. Give a reason for your answer. [3]
\end{enumerate}
\hfill \mbox{\textit{WJEC Unit 4 2018 Q8 [9]}}