Smooth ring on string

3
\includegraphics[max width=\textwidth, alt={}, center]{2a680bda-4ba2-44eb-8592-95b4e1aed263-04_337_661_262_740} A smooth ring \(R\) of mass 0.2 kg is threaded on a light string \(A R B\). The ends of the string are attached to fixed points \(A\) and \(B\) with \(A\) vertically above \(B\). The string is taut and angle \(A B R = 90 ^ { \circ }\). The angle between the part \(A R\) of the string and the vertical is \(60 ^ { \circ }\). The ring is held in equilibrium by a force of magnitude \(X \mathrm {~N}\), acting on the ring in a direction perpendicular to \(A R\) (see diagram). Calculate the tension in the string and the value of \(X\).

2
\includegraphics[max width=\textwidth, alt={}, center]{308cecda-3bc2-4113-b7dd-ed317c5f32c5-03_638_554_260_792} The diagram shows a smooth ring \(R\), of mass \(m \mathrm {~kg}\), threaded on a light inextensible string. A horizontal force of magnitude 2 N acts on \(R\). The ends of the string are attached to fixed points \(A\) and \(B\) on a vertical wall. The part \(A R\) of the string makes an angle of \(30 ^ { \circ }\) with the vertical, the part \(B R\) makes an angle of \(40 ^ { \circ }\) with the vertical and the string is taut. The ring is in equilibrium. Find the tension in the string and find the value of \(m\).
\includegraphics[max width=\textwidth, alt={}, center]{308cecda-3bc2-4113-b7dd-ed317c5f32c5-04_521_707_259_719} A block of mass 10 kg is at rest on a rough plane inclined at an angle of \(30 ^ { \circ }\) to the horizontal. A force of 120 N is applied to the block at an angle of \(20 ^ { \circ }\) above a line of greatest slope (see diagram). There is a force resisting the motion of the block and 200 J of work is done against this force when the block has moved a distance of 5 m up the plane from rest. Find the speed of the block when it has moved a distance of 5 m up the plane from rest.

3
\includegraphics[max width=\textwidth, alt={}, center]{d5acfe31-8614-4508-ac5b-865e15a1f539-2_661_565_1069_790} A small smooth ring \(R\) of weight 8.5 N is threaded on a light inextensible string. The ends of the string are attached to fixed points \(A\) and \(B\), with \(A\) vertically above \(B\). A horizontal force of magnitude 15.5 N acts on \(R\) so that the ring is in equilibrium with angle \(A R B = 90 ^ { \circ }\). The part \(A R\) of the string makes an angle \(\theta\) with the horizontal and the part \(B R\) makes an angle \(\theta\) with the vertical (see diagram). The tension in the string is \(T \mathrm {~N}\). Show that \(T \sin \theta = 12\) and \(T \cos \theta = 3.5\) and hence find \(\theta\).

2
\includegraphics[max width=\textwidth, alt={}, center]{918b65cc-617d-4942-8d96-b02eef21e417-2_471_621_870_762} A smooth ring \(R\) of mass 0.16 kg is threaded on a light inextensible string. The ends of the string are attached to fixed points \(A\) and \(B\). A horizontal force of magnitude 11.2 N acts on \(R\), in the same vertical plane as \(A\) and \(B\). The ring is in equilibrium. The string is taut with angle \(A R B = 90 ^ { \circ }\), and the part \(A R\) of the string makes an angle of \(\theta ^ { \circ }\) with the horizontal (see diagram). The tension in the string is \(T \mathrm {~N}\).

1. Find two simultaneous equations involving \(T \sin \theta\) and \(T \cos \theta\).
2. Hence find \(T\) and \(\theta\).

3
\includegraphics[max width=\textwidth, alt={}, center]{fcd2b219-d9b4-4972-b8fe-25cf543b9054-2_438_621_1676_762} A light inextensible string has its ends attached to two fixed points \(A\) and \(B\), with \(A\) vertically above \(B\). A smooth ring \(R\), of mass 0.8 kg , is threaded on the string and is pulled by a horizontal force of magnitude \(X\) newtons. The sections \(A R\) and \(B R\) of the string make angles of \(50 ^ { \circ }\) and \(20 ^ { \circ }\) respectively with the horizontal, as shown in the diagram. The ring rests in equilibrium with the string taut. Find

1. the tension in the string,
2. the value of \(X\).

1. \begin{figure}[h] \end{figure} Figure 1 shows a small smooth ring threaded onto a light inextensible string.
One end of the string is attached to a fixed point \(A\) on a horizontal ceiling and the other end of the string is attached to a fixed point \(B\) on the ceiling. A horizontal force of magnitude 2 N acts on the ring so that the ring rests in equilibrium at a point \(C\), vertically below \(B\), with the string taut. The line of action of the horizontal force and the string both lie in the same vertical plane. The angle that the string makes with the ceiling at \(A\) is \(\theta\), where \(\tan \theta = \frac { 3 } { 4 }\)
The tension in the string is \(T\) newtons. The mass of the ring is \(M \mathrm {~kg}\).

1. Find the value of \(T\)
2. Find the value of \(M\)

1
\includegraphics[max width=\textwidth, alt={}, center]{99d30766-9c1b-43a8-986a-112b78b08146-2_508_501_274_822} A light inextensible string has its ends attached to two fixed points \(A\) and \(B\). The point \(A\) is vertically above \(B\). A smooth ring \(R\) of mass \(m \mathrm {~kg}\) is threaded on the string and is pulled by a force of magnitude 1.6 N acting upwards at \(45 ^ { \circ }\) to the horizontal. The section \(A R\) of the string makes an angle of \(30 ^ { \circ }\) with the downward vertical and the section \(B R\) is horizontal (see diagram). The ring is in equilibrium with the string taut.

1. Give a reason why the tension in the part \(A R\) of the string is the same as that in the part \(B R\).
2. Show that the tension in the string is 0.754 N , correct to 3 significant figures.
3. Find the value of \(m\).

6
\includegraphics[max width=\textwidth, alt={}, center]{ce4c43e6-da4f-4c02-ab0f-01a21717949c-3_348_1109_1345_516} A small smooth ring \(R\) of weight 7 N is threaded on a light inextensible string. The ends of the string are attached to fixed points \(A\) and \(B\) at the same horizontal level. A horizontal force of magnitude 5 N is applied to \(R\). The string is taut. In the equilibrium position the angle \(A R B\) is a right angle, and the portion of the string attached to \(B\) makes an angle \(\theta\) with the horizontal (see diagram).

1. Explain why the tension \(T \mathrm {~N}\) is the same in each part of the string.
2. By resolving horizontally and vertically for the forces acting on \(R\), form two simultaneous equations in \(T \cos \theta\) and \(T \sin \theta\).
3. Hence find \(T\) and \(\theta\).

2. \begin{figure}[h] \end{figure} Figure 2 shows a washing line suspended at either end by vertical rigid poles. A jacket of mass 0.7 kg is suspended in equilibrium part of the way along the line. The sections of the washing line on either side of the jacket make angles of \(35 ^ { \circ }\) and \(40 ^ { \circ }\) with the horizontal.

1. Find the tension in the washing line on each side of the jacket.
2. Explain why, in practice, the angles are likely to be very similar in value.

8 A crate, of mass 200 kg , is initially at rest on a rough horizontal surface. A smooth ring is attached to the crate. A light inextensible rope is passed through the ring, and each end of the rope is attached to a tractor. The lower part of the rope is horizontal and the upper part is at an angle of \(20 ^ { \circ }\) to the horizontal, as shown in the diagram.
\includegraphics[max width=\textwidth, alt={}, center]{fe8c1ea4-cf4d-4741-8af5-03e8c2c88559-5_344_1186_518_420} When the tractor moves forward, the crate accelerates at \(0.3 \mathrm {~m} \mathrm {~s} ^ { - 2 }\). The coefficient of friction between the crate and the surface is 0.4 . Assume that the tension, \(T\) newtons, is the same in both parts of the rope.

1. Draw and label a diagram to show the forces acting on the crate.
2. Express the normal reaction between the surface and the crate in terms of \(T\).
3. Find \(T\).

1
\includegraphics[max width=\textwidth, alt={}, center]{4c8f0d10-ea1e-4aee-870d-71a52dd948ed-02_508_501_274_822} A light inextensible string has its ends attached to two fixed points \(A\) and \(B\). The point \(A\) is vertically above \(B\). A smooth ring \(R\) of mass \(m \mathrm {~kg}\) is threaded on the string and is pulled by a force of magnitude 1.6 N acting upwards at \(45 ^ { \circ }\) to the horizontal. The section \(A R\) of the string makes an angle of \(30 ^ { \circ }\) with the downward vertical and the section \(B R\) is horizontal (see diagram). The ring is in equilibrium with the string taut.

1. Give a reason why the tension in the part \(A R\) of the string is the same as that in the part \(B R\).
2. Show that the tension in the string is 0.754 N , correct to 3 significant figures.
3. Find the value of \(m\).