If a vector Ā is making an angle "∅" with positive y-axis then which of the following is correct.?
Correct answer: C. Ay= ACos∅
- A. Ax= ACos∅
- B. Ay= ASin∅
- C. Ay= ACos∅
- D. None
Explanation
When a vector of magnitude A makes an angle φ with the positive y-axis, its y-component is adjacent to the angle, so Ay = A cosφ. The x-component is opposite the angle, so Ax = A sinφ. Students often choose Ax = A cosφ by remembering the cosine rule without checking which axis forms the angle.
Last updated
About Rectangular Components
A vector is resolved into perpendicular horizontal and vertical components using trigonometric relations, usually as Ax = A cos θ and Ay = A sin θ when θ is measured from the horizontal. Questions involve signs in different quadrants, reconstructing a resultant from components, and using components to analyse equilibrium.
Practise Vectors and Equilibrium
431 free Vectors and Equilibrium MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Physics questions like this
Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.