| Exam Board | SPS |
|---|---|
| Module | SPS ASFM Mechanics (SPS ASFM Mechanics) |
| Year | 2021 |
| Session | May |
| Topic | Work done and energy |
| Type | Motion on rough inclined plane |
| Difficulty | Moderate -0.3 This is a standard A-level mechanics question involving energy methods and friction on an inclined plane. Parts (a)-(c) follow a routine progression (PE loss → work-energy principle → coefficient of friction), while part (d) applies the same coefficient to a different scenario. All techniques are textbook standard with no novel problem-solving required, making it slightly easier than average. |
| Spec | 3.03v Motion on rough surface: including inclined planes6.02a Work done: concept and definition6.02d Mechanical energy: KE and PE concepts6.02i Conservation of energy: mechanical energy principle |
At a demolition site, bricks slide down a straight chute into a container. The chute is rough and is inclined at an angle of $30°$ to the horizontal. The distance travelled down the chute by each brick is $8$ m. A brick of mass $3$ kg is released from rest at the top of the chute. When it reaches the bottom of the chute, its speed is $5$ m s$^{-1}$.
\begin{enumerate}[label=(\alph*)]
\item Find the potential energy lost by the brick in moving down the chute.
\end{enumerate}
(2)
\begin{enumerate}[label=(\alph*)]
\setcounter{enumi}{1}
\item By using the work-energy principle, or otherwise, find the constant frictional force acting on the brick as it moves down the chute.
\end{enumerate}
(5)
\begin{enumerate}[label=(\alph*)]
\setcounter{enumi}{2}
\item Hence find the coefficient of friction between the brick and the chute.
\end{enumerate}
(3)
Another brick of mass $3$ kg slides down the chute. This brick is given an initial speed of $2$ m s$^{-1}$ at the top of the chute.
\begin{enumerate}[label=(\alph*)]
\setcounter{enumi}{3}
\item Find the speed of this brick when it reaches the bottom of the chute.
\end{enumerate}
(5)
\hfill \mbox{\textit{SPS SPS ASFM Mechanics 2021 Q6}}