Tension: The Force In Any Stretched Body

NAME: INSTRUCTOR: INSTITUTION: DATE: Tension is the force that arises in any stretched body. The tension in a spring is equal and opposite to its weight. This force is also as a result of electromagnetic interactions between the molecules of a material making up the spring. When a spring is overstretched, it pulls out from its coiled shape into a long wire, then the spring is said to be under tension. In physics, tension may also be described as the pulling force transmitted axially by the means of a string, cable, chain or similar one-dimensional continuous object (Tsokos, 2010). It may also be described as the action-reaction pair of forces acting at each end. There are also other forces that are related to the tension of a spring. They include contact force and expansion force. Contact force refers to a push produced when two objects are pressed together while their surface atoms keep them together. Expansion force refers to a push found in a compressed spring (Katz, 2016).The tension in a spring is always proportional and opposite to the extension. That is, the more you want to extend and compress the spring, the bigger the force required to pull or push with. This can be explained better using the following expression; T=kx. Whereby k= the constant of proportionality known as the spring constant. The figure below shows tension force in a string, For example, when a string hangs from the ceiling and mass is tied on the other end then the tension is said to have been created. Tension force then pulls down the ceiling from the point of support and at the point where the mass is tied it acts upwards on it (Tsokos, 2010). The figure 3.3 above shows how tension is directed along the string. Mostly, the spring is considered massless not because it has no mass, but because its mass is very less compared to any other mass. Therefore, T-tension is always the same all over the string and its movement is also along the string. Types of springs. Springs are used as an everyday tool used by most people and their inertia are often neglected by assuming its mass is less. It’s always a very casual activity that a spring when stretched it undergoes displacement. That is, it gets compressed and when it is released it comes to the equilibrium position. It also tells that springs to apply an equal as well as opposite force on a body which stretches or compresses it. The springs are classified according to how the load force is applied to them. They include, tension/extension spring that is designed to operate with a tension load and so the spring stretches as the load is applied to it.The second type is the compression spring that is designed to operate with a compression load, so the spring gets shorter as the load is applied to it.Torsion spring that is unique from the rest is also known as the a torque. There are also other springs like constant spring, variable spring, machined spring and flat spring. (Tsokos, 2010). The following is a worked out example. A 0.50m spring with constant 100N\M hangs from the ceiling. A 2.0kg block is tied to the spring. How much does the spring stretch? (Use g=10m\s squared). Solution. The 2.0 kg mass applies a 20N force downwards on the spring (because this force is focused by the gravity-the pull of the earth).In order to support the 20N downwards force, the spring must apply 20N force upwards. Assume upwards is positive while downwards is negative, Fs=-kd 20N= (-100N\m) d D=-0.20m Thus the spring will stretch downwards by 0.20m and the total length of the spring will be 0.70m but the stretch alone is 20cm. Example2. A single spring is stretched by x when mass m is attached. An identical spring is then joined in series to the first spring. How much will the two springs stretch when a mass m is attached? (Assume the springs have legible mass). Solution. The tension along the springs with negligible mass has to be constant at all points. Since the spring holding the mass is equal to mg the tension of the spring will also be in mg. Each spring stretches by x causing a total stretch of 2x.Therefore two identical springs connected in a series will stretch twice as much as one spring would have stretched. Another example that demonstrates spring tension is a rope. According to (Tsokos, 2010), a string or rope that is not tout is said to have zero or no tension. The figure above shows different examples of tension forces. According to Newton's law of motion, under spring tension, there is a special type of force called spring force. It is also known as a restoring force because it is directed so as to return or restore the spring to its original relaxed state. The further the string is stretched apart, the stronger the restoring force. In most cases, the forces exerted in springs is always proportional to how far the attached block is displaced from the relaxed position and by doing so, the spring is said to have obeyed the Hook’s Law(Katz,2016) The hook's law can, therefore, be explained better using the following mathematical formula, Whereby H as the subscript, stands for Hook. The negative sign shows that the restoring force is in the direction opposite to the direction of displacement (Katz, 2016).The constant k, also known as the spring constant, is used to measure the stiffness of the spring and the SI unit of K is newton’s per meter (N\M).The following diagrams demonstrate the behavior of a spring in different conditions. Figure A .shows that the spring is relaxed therefore does not exert force. Figure B.shows a compressed spring that is pushed on the block. It also demonstrates contact force. Figure C. Shows a stretched spring pulls on the block. It also demonstrates contact force. The ability of the spring to stretch and relax back to its original state has enabled to have many uses, for example, the springs are used in mechanical systems to make objects like retractable pens and some mattresses. They have scales that are used to measure the weight of an object. When you want to read the measurement of an object, you hung it on the spring scale or put it on top of the scale. Then the weight of the object is determined by reading the magnitude of the spring force on that object. The difference between spring force and tension of a spring. Spring force is the reactive force that is developed on a spring due to change in its absolute length and it is developed as a result of both compression and extension of the free length of a spring. Spring tension, on the other hand, is also a reactive force that is developed in a spring due to an extension of its free length on a normal spring. The elasticity of the spring. The ability of the spring to return back to its original size and shape after being deformed is known as elasticity. This property has enabled the application of springs in car suspensions and retractable pens. The special types of springs used are called the coiled springs. They work under Hook’s law of elasticity. Spring constant. Spring constant is the force applied if the displacement in the spring is uniform. A spring constant is calculated using Hook’s law which states that the restoring force of a spring is directly proportional to a small displacement. Displacemen...