chapter 9 sci

• Pressure can be calculated using the formula: pressure = force / area.
• Work is done when a force moves an object through a distance in the same direction the force is acting.
• When someone sucks on a straw, some air is removed from it. The air pressure inside the straw decreases and becomes lower than the surrounding atmosphere pressure. The higher atmospheric pressure pushes the liquid up the straw and into the mouth
• Air is pushed out from under the suction cup. the air pressure between the suction cup and the surface decreases. It becomes lower than the atmospheric pressure. The higher atmospheric pressure holds the suction cup in place on the surface.
• The greater the depth below the water's surface, the more pressure there is exerted by the weight of the overlying water.
• pressure is affected by the area of contact and the distance between the surfaces of the object and the surface
• weight is the amount of gravitational force acting on an object, measured in newtons (N)
• weight can change with location, but mass remains constant regardless of location.
• Chemical potential energy -> heat energy ->kinetic energy -> electrical energy (fossil fuels)
• light energy ->electrical energy (solar energy)
• gravitational potential energy -> kinetic energy -> electrical energy (hydroelectric energy)
• kinetic energy ->electrical energy (wind energy)
• heat energy ->kinetic energy ->electrical energy (geothermal energy)
• chemical potential energy ->heat energy -> kinetic energy (biofuels)
• nuclear energy ->heat energy ->kinetic energy -> electrical energy (nuclear energy)
• nuclear energy is a clean source of energy and requires less space to generate energy, but is dangerous
• biofuels are renewable, but they release carbon dioxide when they are burnt
• geothermal energy is renewable, but it requires the clearing of huge areas of land, which leads to loss of habitats.
• wind energy is renewable, but requires a lot of space to be cleared.
• hydroelectric power is renewable, but damming rivers can cause flooding downstream and disrupt ecosystems.
• solar energy is renewable, but it is not efficient.
• fossil fuels release carbon dioxide when burnt