application of forces and transfer of energy Flashcards
how are volcanic eruptions formed?
rocks melt to form magma. the earth also moves violently when magma is pushed out towards earth’s surface with great force.
what is are tropical cyclones ?
what are its consequences?
a tropical cyclone are longer and more intense storms. they are usually accompanied by heavy and strong rains. this results in flooding. the rapidly moving floodwaters can exert forces on the soil and loosen it, causing landslides.
strong winds can exert great forces on objects in its way. the broken parts of objects that are carried away by the strong winds can cause more damage to the surrounding objects, or hit people and injure them.
how are tsunamis formed?
what are consequences of them?
vigorous movement of the ocean floor caused by earthquakes or volcanic eruptions displaces the ocean water and results in tsunamis.
the potential energy of ocean water increases greatly as the waves reach great heights. as the waves move at high speed towards the shore , the potential energy in the waves is converted to kinetic energy. when the waves hit the shore, it causes erosion of coastlines, damage to buildings and the environment , and the loss of lives.
how are earthquakes formed?
when a plate slides over or against another plate, the force exerted between the two plates may result in a great amount of energy released.
examples of contact forces? + what they do
- friction [is the force that opposes motion between two surfaces in contact]
- elastic force [is the force acting on a stretched or compressed elastic object to return to its original shape]
example of non-contact forces? + what they do
- gravitational force [is a force that attracts two objects towards each other]
- magnetic force [is the force exerted between a magnet and another magnetic material such as iron or steel]
what is weight? + si unit
weight is the measure of the gravitational force acting on an object
SI unit: newton
what is mass? + si unit
mass is the amount of matter in an object
SI unit: kilogram
does mass and weight change based on their locations?
the amount or quantity of matter does not change regardless of location; mass remains the same
the weight of an object depends on the gravitational force exerted on the object, which may change with its location
what is a pivot?
a force applied on an object that causes a turning effect about a fixed point
what is pressure?
it is the effect of force acting on an object
how is pressure defined? + unit of pressure
pressure is defined as force per unit area
pressure = newton / square metre
unit of pressure: pascal (Pa) or N/m2
what is atmospheric pressure?
it is when a layer of air particles pushes down on earth’s surface due to gravitational force. the layer of air also exerts pressure on us and all objects on earth
how to straws work? [in terms of pressure]
when a person sucks on a straw, some air is removed from it. the air pressure inside the straw decreases and becomes lower than the surrounding atmospheric pressure. the higher atmospheric pressure pushes the liquid up the straw
how does suction cups work? [ in terms of pressure ]
when a suction cup is pressed against a smooth surface, air is pushed out from under the suction cup. the air 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.
how do we determine if work is done?
- a force is applied on the object
- the object moves
- the object moves in the same direction as the force applied on it [energy is transferred]
what happens if work is not done?
no energy is transferred even though a force is applied
SI unit of transfer of energy or amount of work done
joule (J)
conversion of energy of a rollercoaster?
gravitational potential energy (at a high point) —> kinetic energy (at a lower point)
how are fossil fuels formed? + energy conversion of fossil fuels
fossil fuels are formed from the remains of dead plants and animals buried in earth millions of years ago.
when fossil fuels [chemical potential energy] are burnt and they undergo a chemical process in a power station, it releases [heat energy]. the [heat energy] can be converted to [kinetic energy] in a turbine, which can be used to produce [electrical energy].
impacts of the use of fossil fuels on our environment
the burning of fossil fuels releases air pollutants and greenhouse gases into the environment, which contribute to global warming and increase the rate of climate change, which can cause natural disasters to be more intense
energy conversion of solar energy
light energy (sun) —> electrical energy through solar panels
impact of the use of solar energy on the environment
- solar energy can generate electricity without releasing air pollutants and greenhouse gases.
- the process of harnessing solar energy has minimal impact on the environment
what is hydroelectric energy? +energy conversion pf hydroelectric energy
hydroelectric energy is electrical energy generated by turbines when moving water powers them.
the reservoir water stores [gravitational potential energy] behind the dam. as water runs down the turbine passageway at high speed, [gravitational potential energy] is converted to [kinetic energy]. as the moving water turns the blade of the turbine, [kinetic energy] of the water is converted to [kinetic energy of the turning blades]. the [kinetic energy] is converted to [electrical energy] in the generator
