Question
A uniform metre rule is pivoted at the 34.0 cm mark, as shown.
The rule balances when a 64 g mass is hung from the 4.0 cm mark.
What is the mass of the metre rule?
(A) 38$_{g}$
(B) 44$_{g}$
(C) 120$_{g}$
(D) 136$_{g}$
Answer/Explanation
Ans: C
Question
A uniform rod XY of weight 10.0 N is freely hinged to a wall at X. It is held horizontal by a force F acting from Y at an angle of $30^{\circ}$ to the horizontal, as shown.
What is the value of F?
(A) 5.0 N
(B) 8.7 N
(C) 10 N
(D) 20 N
▶️Answer/Explanation
Ans: B
Question
The diagram shows a ball of weight W hanging in equilibrium from a string.
The string is at an angle θ to the vertical. The tension in the string is T. The ball is held away from the wall by a horizontal force P from a metal rod.
Which relationship between the magnitudes of T, P and W is correct?
(A) P = T cosθ and W = T sinθ
(B) T = P + W
(C) T²= P²+ W²
(D) W = P tanθ and W = T cosθ
▶️Answer/Explanation
Ans: C
Question
A rod is pivoted at one end. Initially the angle \(\Theta\) of the rod to the horizontal is \(0\circ \) . The weight of the rod causes a moment M about the pivot. The rod is then rotated in the vertical plane so that the angle \(\Theta\) of the rod increases from \(0\circ \) to \(180\circ \) . Which graph shows the variation of M with \(\Theta\) ?
▶️Answer/Explanation
Ans D