Physics · Grades 10–12
Work by an angled force
θ is the angle between the force and displacement, not an arbitrary drawing angle.
Rule and assumptions
θ is the angle between the force and displacement, not an arbitrary drawing angle.
W = Fd cos θ
Worked examples
A constant 60 N force acts through a 13 m displacement. The cosine of the angle between them is -0.5. Find the work by this force. Round to 3 decimal places if needed. Answer in J.
W = Fd cos θ 60 × 13 × (-0.5) = -390
-390 J
A constant 46 N force acts through a 14 m displacement. The cosine of the angle between them is 0.5. Find the work by this force. Round to 3 decimal places if needed. Answer in J.
W = Fd cos θ 46 × 14 × (0.5) = 322
322 J
Try two questions
A constant 35 N force acts through a 6 m displacement. The cosine of the angle between them is 0.5. Find the work by this force. Round to 3 decimal places if needed. Answer in J.
A constant 64 N force acts through a 7 m displacement. The cosine of the angle between them is -1. Find the work by this force. Round to 3 decimal places if needed. Answer in J.
Answers and reasoning
Answers and marking notes
- 105 J
W = Fd cos θ 35 × 6 × (0.5) = 105
- -448 J
W = Fd cos θ 64 × 7 × (-1) = -448
Further reading and review references
These are reference links, not copied exercises, institutional endorsement or proof of independent review.
Learning preview · independent educational and translation review required. Suggested grades are not official curriculum alignment.