JK-TK/GRADE-8-TERM-2 huggingface dataset:
For the same applied force, pressure is higher with a smaller area and it is less with a large area. It is easier to cut with a sharp knife, axe, panga than trying to cut with a blunt knife, axe or panga. A farm tractor has wide wheels that prevent it from sinking into the soil because pressure is distributed over a large area of the wide wheels. A trailer or trailers are fitted with many wheels to reduce pressure exerted on the road since the wheels increase surface area. Demonstrating pressure exerted by objects of different cross-sectional area. The block below has a weight of 20kg. Use it to:Determine maximum pressure it exerts in a surface. Determine the minimum pressure it exerts on a surface. G 10N Kg1m1.5m2mPressure is calculated by dividing Force over Area F A From the block above Force, F is given as 20kg. Change 20k into Newtons N this is done by multiplying the weight given in Kg by the gravitational force g 10N kg Therefore, F 20 x 10N kg 200 N. To calculate the maximum m pressure the block exerts on the surface. To calculate minimum pressure the block exerts on the surface. Use the force provided divided by the largest area of the block. If a force is exerted on a small area of contact, it will exert higher or more pressure than if the same force is exerted over a large area. Since weight of force of a brick is constant does not change , a higher pressure is exerted on the sand when the brick lands on narrow face than when it lands on the wide face. The narrow face therefore, produces a deeper depression on the sand than the wide face. Example 2. Suppose the mass of a learner is 40kg and the total area of her feet is 500cm2. What pressure does the girl exert when standing on one of her feet? Assume het feet have equal area. G 10g Kg Solution. Pressure F A. Force the student exerts on the ground is her weight, which is 40kg x 10N Kg. 400 N. Area 500cm2 2 250 cm2. Change area form cm2 to m2. 1m2 10000cm2. ?
Change area form cm2 to m2. 1m2 10000cm2. ? 250cm2 250 10000 0.025m2Substitute the values into the formula. Pressure Force Area 400N 0.025m216,000N m2Example 3. A mass of 50kg exerts a pressure of 2000N m2. What area is in contact with the ground? Pressure Force Area Pressure 2000N m2. Area? To be determined. 2000N m2 50kg x 10N kgAreaTherefore, area Force Pressure. Force 500N. Pressure is given as 2000N m2 Area 500N 2000N m2. 0.25m2. Pressure in liquids. Demonstrating that a liquid exerts equal pressure at the same depth. Use an empty bottle or cylindrical container. Drill holes all round near the bottom of the bottle at the same height from the bottom of the bottle. Close the holes using cellotape and fill the bottle with water, remove the cellotape at once. Explain your observation. Observation and explanation. If you observe the jest coming of the bottle, you will notice that they fall at equal distances on all sides of the bottle only if the pressure of water at the depth of the holes in the bottle is the same. Therefore, we conclude that:A liquid exerts pressure on the walls of its container. A liquid exerts pressure at the same depth. The formation of fountains of water from the leaking pipes of water supply tells is that water exerts pressure on the walls of its container. Demonstrating that pressure in liquids increases with depth. ABCIf a bottle is filled with water and equal size holes made from the bottom to the tops as show above. You will observe that after opening all the holes, water jet fall in different horizontal distances depending on the depth they are on the bottle. For example, in the diagram above. The water jet C is observed to move the farthest horizontally. As the depth from the surface decreases like in hole A and B, the distance from the container to where the jet strikes decrease, indicating a lower pressure by the water. The weight of the liquid acts downwards. The more the depth, the more the liquid is above the point.
As the depth from the surface decreases like in hole A and B, the distance from the container to where the jet strikes decrease, indicating a lower pressure by the water. The weight of the liquid acts downwards. The more the depth, the more the liquid is above the point. This increases the weight causing more pressure at that level. The pressure at this level acts on the container, on any object in water and on the liquid below this level. Determining pressure in liquids. The pressure exerted by a liquid at a particular point is determined by the following:Depth. Density of the liquid. Acceleration due to gravity g 10N Kg Formular for pressure at appoint in liquidsPressure Force Area F A Pressure exerted at the bottom of the cylinder F A Volume of the liquid base are x height Ah. Mass of the liquid; m volume x density Ah x p. Weight of the liquid mass x gravitational field strength force exerted. Weight of the liquid; W F mg Ah g. Therefore pressure Ah gAP h g. From the formula, pressure at a given point in liquids depends on the following:Depth or height of the liquid. Density of the liquid. Acceleration due to gravity g 10N kg Applications of pressure in solids and liquids in day-to-day life. Applications of pressure in solids. Animals such as elephants and camels have broad feet to reduce the pressure exerted on the ground when walking. Cutting tool- cutting tools like a panga, saw and knives have very small surface area of contact at their cutting edges. When a force is applied to cut an object, the small surface area results in high pressure which makes cutting easier. Wooden plank- when a wooden plank is placed on a soft ground surface it increases the surface area in contact between the wheel barrow and the ground. As a result, the pressure exerted on the ground by the wheel barrow is reduced. Digging-edge of a jembe is sharp to reduce surface area when jembe is driven into the ground. This exerts high pressure making digging easier. Football boots-they have studs that are sharp to reduce area of contact and increase pressure on the football pitch. This provides a player with a better grip on the ground. School bag shoulder pads- they are made wide so that they reduce the pressure applied on the shoulder.
Football boots-they have studs that are sharp to reduce area of contact and increase pressure on the football pitch. This provides a player with a better grip on the ground. School bag shoulder pads- they are made wide so that they reduce the pressure applied on the shoulder. This makes one comfortable as narrow strap increase pressure on the shoulders causing pain. Application of pressure in liquids. Construction of dams-walls of a dam have thicker bottom to help withstand high pressure of water due to depth. Water supply-water tanks are erected high or elevated on high grounds so that water has enough pressure to flow to a house. Intravenous transfusion IV -this a is method of putting fluids, for example blood, into the bloodstream of a patient. In this method, a bottle is hung at high position to ensure that the fluid in the IV bottle have enough pressure to flow into the vein of the patient.