Moderate -0.8 This is a straightforward application of the work formula W = Fs cos θ with all values given except θ. Students need to find distance (s = vt = 20m), then solve 350 = 20 × 20 × cos θ for θ. It's more routine than average A-level questions since it requires only one formula and basic algebraic manipulation with no conceptual subtlety.
1 A child is pulling a toy block in a straight line along a horizontal floor.
The block is moving with a constant speed of \(2 \mathrm {~ms} ^ { - 1 }\) by means of a constant force of magnitude 20 N acting at an angle of \(\theta ^ { \circ }\) above the horizontal.
The work done by the force in 10 s is 350 J .
Calculate the value of \(\theta\).
1 A child is pulling a toy block in a straight line along a horizontal floor.\\
The block is moving with a constant speed of $2 \mathrm {~ms} ^ { - 1 }$ by means of a constant force of magnitude 20 N acting at an angle of $\theta ^ { \circ }$ above the horizontal.
The work done by the force in 10 s is 350 J .
Calculate the value of $\theta$.
\hfill \mbox{\textit{OCR MEI Further Mechanics A AS 2019 Q1 [3]}}