Razita Rabiah | Uitm Perak (original) (raw)

Papers by Razita Rabiah

Objective: To illustrate the application of Archimedes' Principle to the determination of density... more Objective: To illustrate the application of Archimedes' Principle to the determination of density. DISCUSSION: Archimedes' principle states that a body immersed in a fluid experiences an upward force due to the surrounding fluid and that this force is equal to the weight of the fluid displaced by the body. We can make use of this principle to determine the density of various substances. Density is defined as mass per unit volume, or in equation form: , where is the density, m is the mass, and V is the volume Consider a body immersed in water, as in Figure 1, with a density greater than that of water. To keep the object from sinking, we support it with a string. The tension, T, in the string plus the buoyant force, B, of the surrounding water is just sufficient to balance the weight, W, of the object. That is, (1) We can use this equation to find the buoyant force by weighing the body in water. To find T, provided we suspend the body from the weighing scales using the string. The buoyant force is equal to the weight of the displaced water. The volume of the displaced water is the same as the volume of the body that is submerged. Therefore the ratio W / B is the weight of the object to the weight of an equal volume, V of water. Keeping in mind that weight is W=mg, dividing both numerator and denominator by gV, where g is the acceleration due to gravity and the volumes are equal, we obtain the ratio of density of the object to the density of water. That is, (2) Here F 0 7 2 b and F 0 7 2 w are the densities of the body of water respectively. By definition, the density of water is exactly 1000 kg/m 3 , or 1 g/cm 3 and so Equation 2 can be used to calculate the density of the body. If the body ordinarily floats in water, the buoyant force equals its weight. To be able to use Equation 2 to determine the density, it is necessary that the body be completely submerged in the water. We do so by attaching a sinker, as seen in Figure 2. A tension T lower in the lower string, along with the buoyant force on the sinker, supports the sinker against the force of gravity. Note that this tension T lower is the same whether the body to be measured is covered with water or not, as long as the sinker is immersed. This provides a straightforward way to measure the buoyant force B on the body.-1

Objective: To illustrate the application of Archimedes' Principle to the determination of density... more Objective: To illustrate the application of Archimedes' Principle to the determination of density. DISCUSSION: Archimedes' principle states that a body immersed in a fluid experiences an upward force due to the surrounding fluid and that this force is equal to the weight of the fluid displaced by the body. We can make use of this principle to determine the density of various substances. Density is defined as mass per unit volume, or in equation form: , where is the density, m is the mass, and V is the volume Consider a body immersed in water, as in Figure 1, with a density greater than that of water. To keep the object from sinking, we support it with a string. The tension, T, in the string plus the buoyant force, B, of the surrounding water is just sufficient to balance the weight, W, of the object. That is, (1) We can use this equation to find the buoyant force by weighing the body in water. To find T, provided we suspend the body from the weighing scales using the string. The buoyant force is equal to the weight of the displaced water. The volume of the displaced water is the same as the volume of the body that is submerged. Therefore the ratio W / B is the weight of the object to the weight of an equal volume, V of water. Keeping in mind that weight is W=mg, dividing both numerator and denominator by gV, where g is the acceleration due to gravity and the volumes are equal, we obtain the ratio of density of the object to the density of water. That is, (2) Here F 0 7 2 b and F 0 7 2 w are the densities of the body of water respectively. By definition, the density of water is exactly 1000 kg/m 3 , or 1 g/cm 3 and so Equation 2 can be used to calculate the density of the body. If the body ordinarily floats in water, the buoyant force equals its weight. To be able to use Equation 2 to determine the density, it is necessary that the body be completely submerged in the water. We do so by attaching a sinker, as seen in Figure 2. A tension T lower in the lower string, along with the buoyant force on the sinker, supports the sinker against the force of gravity. Note that this tension T lower is the same whether the body to be measured is covered with water or not, as long as the sinker is immersed. This provides a straightforward way to measure the buoyant force B on the body.-1