Standard +0.3 This is a straightforward work-energy problem requiring students to apply the work-energy principle with multiple forces (applied force at an angle, weight, resistance). While it involves several components and careful bookkeeping of energy terms, it follows a standard template with no novel insight required—slightly easier than average due to its methodical nature.
7
\includegraphics[max width=\textwidth, alt={}, center]{ffefbc81-402f-4048-8741-23c8bae30d5a-3_246_1006_1781_571}
A block of mass 60 kg is pulled up a hill in the line of greatest slope by a force of magnitude 50 N acting at an angle \(\alpha ^ { \circ }\) above the hill. The block passes through points \(A\) and \(B\) with speeds \(8.5 \mathrm {~m} \mathrm {~s} ^ { - 1 }\) and \(3.5 \mathrm {~m} \mathrm {~s} ^ { - 1 }\) respectively (see diagram). The distance \(A B\) is 250 m and \(B\) is 17.5 m above the level of \(A\). The resistance to motion of the block is 6 N . Find the value of \(\alpha\). [0pt]
[11]
7\\
\includegraphics[max width=\textwidth, alt={}, center]{ffefbc81-402f-4048-8741-23c8bae30d5a-3_246_1006_1781_571}
A block of mass 60 kg is pulled up a hill in the line of greatest slope by a force of magnitude 50 N acting at an angle $\alpha ^ { \circ }$ above the hill. The block passes through points $A$ and $B$ with speeds $8.5 \mathrm {~m} \mathrm {~s} ^ { - 1 }$ and $3.5 \mathrm {~m} \mathrm {~s} ^ { - 1 }$ respectively (see diagram). The distance $A B$ is 250 m and $B$ is 17.5 m above the level of $A$. The resistance to motion of the block is 6 N . Find the value of $\alpha$.\\[0pt]
[11]
\hfill \mbox{\textit{CAIE M1 2014 Q7 [11]}}