Moderate -0.8 This is a straightforward application of the work formula W = Fs cos(α). Students substitute given values (8200 = 180 × 50 × cos α), rearrange to find cos α, then use inverse cosine. It requires only direct recall of one formula and basic algebraic manipulation with no problem-solving insight needed.
1 A block is pulled for a distance of 50 m along a horizontal floor, by a rope that is inclined at an angle of \(\alpha ^ { \circ }\) to the floor. The tension in the rope is 180 N and the work done by the tension is 8200 J . Find the value of \(\alpha\).
1 A block is pulled for a distance of 50 m along a horizontal floor, by a rope that is inclined at an angle of $\alpha ^ { \circ }$ to the floor. The tension in the rope is 180 N and the work done by the tension is 8200 J . Find the value of $\alpha$.
\hfill \mbox{\textit{CAIE M1 2011 Q1 [3]}}