Criado por Iona Diack
aproximadamente 9 anos atrás
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Questão | Responda |
What is Fission? | It is the splitting of an atomic nucleus |
What are 2 Fissionable materials? | Uranium 235 Plutonium 239 |
What must happen for fission to occur? | The atomic nucleus must absorb a neutron. |
Why is a neutron fired at the nucleus in fission? | to split the nucleus so it forms two smaller nucleus? |
What happens when the splitting in fissions occurs? | Energy is released along with 2 or 3 more neutrons. These neutrons are then absorbed by other nuclei which then causes the process to repeat. |
How is fission controlled in a reactor tower? | By control rods, which absorb the neutrons if the reaction needs to be slowed down. |
What is fusion? | Two atomic nuclei that join together to form another larger one. |
What happens when fusion occurs occurs? | Energy is released. |
What is an example of a process of fusion? | Where stars gets their energy (they react using fusion) |
What is the first stage in the life cycle of a star? | Stars form from clouds of gas and dust from space and get pulled together by gravitational attraction |
What is the second stage in the life cycle of a star? | A gravitational attraction pulls the particles of dust and rock together and as they move inwards their gravitational potential energy is converted into heat and a protostar is formed. |
What is the third stage in the life cycle of a star? | The forces of gravity pulls the particles inwards and the temperature tries to push the particles outwards, which balancing using hydrogen as a fuel. |
What is the fourth stage in the life cycle of a massive star? | Eventually the hydrogen that is used to fuel the star will run out and when this happens the star becomes colder and redder. This is called the red supergiant. |
What is the Fifth stage in the life cycle of a massive star? | When the star becomes a red supergiant the star will shrink and then explode This is called a Supernova. |
What happens to a heavy star? | The remaining core turns into a black hole. |
What happens to a light star? | The remaining core turns into a neutron star. |
What is the fourth stage in the life cycle of a star in a star like out sun? | It turns into a red giant because the hydrogen runs out. The star becomes redder and colder and starts to swell. |
What happens to a star like our sun after it becomes a red giant? | The red giant turns into a white dwarf which then becomes a black dwarf. |
What does alpha decay involve? | Releasing an Alpha particle. |
What is an alpha particle made up of? | 2 neutrons and 2 Protons |
What happens to an isotope when it releases an alpha particle? | Its atomic number decreases by 2 and its mass number decreases by 4 |
What happens in beta decay? | It turns neutron into a proton. |
What happens to the proton number in beta decay? | The proton number increases. |
What happens to the mass number in beta decay? | It stays the same. |
What is background radiation? | the radiations that is around us all the time in the background. |
What are the three types of radiation? | Alpha, Beta and Gamma |
How many protons are in Alpha? | 2 neutrons, 2 protons |
What is Beta? | A fast moving electron |
What is Gamma? | An electromagnetic wave |
What charge does: a) Alpha have b) Beta Have c) Gamma Have | a) 2+ charge b) -1 Charge c) Neutral |
What is Alpha absorbed by? | Paper |
What is Beta absorbed by? | Aluminium |
What is Gamma absorbed by? | Lead |
What is their ionising powers? a) Alpha b) Beta C) Gamma | a) Highly ionising b) Moderately ionising c) Weakly ionising |
Which type of radiation are deflected by a magnetic or an electronic field ? | Alpha and Beta |
What is the charge of a: A) Neutron B) Proton C) Electron | a) No charge b) Positive c) Negative |
What is an isotope? | an atom of the same element with a different number of neutrons. |
What is a fuse? | a safety device in a circuit that melt if too large a current passes through them. |
What is a fuses main job? | to prevent the device from overheating or catching fire. |
What is a thermistor? | A resistor that changes their resistance depending on the temperature. |
What does AC stand for? | Alternating current |
What does an AC current do? | the current changes direction 50 times every second |
What does DC stand for? | Direct current |
What does a DC current do? | the current flows in one direction and electrons flow around the circuit. |
What graph is this? | A resistor at a constant temperature |
What graph is this? | A Filament lamp |
What graph is this? | A diode |
What is static electricity? | Two objects that are rubbed together, and the electrons from one object move to the other. |
What does static electricity cause? | An overall positive charge on one object and the other object having a negative charge. |
What do like charges and unlike charges do? | Like charges repel Unlike charges attract |
What are neutral objects attracted to? | Possibly and negatively charged objects |
How could you check if an object is charged? | check if the object is attracted to bits of paper, hair or any other charged object to see if it attracts or repels said object. |
What is always conserved? | Momentum (unless there are external forces acting upon it) |
What does the conservation of momentum mean? | It means that the momentum before the collision is equal to the momentum after the collision |
What happens when a force acts upon an object? | The energy is transferred and work is done to the object. |
What is velocity? | It is a speed in a given direction |
What is Acceleration? | It is the rate of the change in velocity |
What is the resultant force? | The sum of the forces acting on an object |
When is the resultant force 0? | When the drag force is equal to the weight of the resultant force. |
How do forces affect sky divers acceleration? | The gravitational pull is greater that the air resistance so the divers speed starts to accelerate The air resistance starts to equal out to the force of gravity so the diver slows down when the parachute is opened the drag then becomes much greater than the gravitational pull, so the diver slows down |
What is the thinking distance? | The distance taken for a driver to see a problem and then apply the breaks. |
What are some factors that affect the thinking distance? | Tiredness Drugs/ Alcohol Distractions Emotions Feeling unwell |
What is the breaking distance? | The distance the car moves after the breaks have been applied until the vehicle stops. |
What are some factors that effect the breaking distance? | Speed the vehicle is travelling at Weather Vehicle Mass/conditions Road conditions |
What is the stopping distance? | The thinking distance and the breaking distance added together |
Where is elastic potential energy stored? | An elastic object when work is done to change its shape |
What does mass tell us? | How much matter and object has |
What is weight? | A force that depends on gravity or mass |
What is work done? | The amount of energy transferred is equal to the work done |
What happens when you move an object against a surface with friction? | the energy gets transformed into heat |
When does friction occur? | When the surface of the object have small bumps on them. |
What does friction produce? | Heat |
What does power tell us? | How much energy is transferred in a second |
What are good at producing static electricity? | Insulators |
What is momentum? | The product of mass and velocity |
What does a velocity time graph tell you? | How an object velocity is changing over time |
What does it mean if there is a smooth slop on a velocity time graph? | The object is accelerating |
What does it mean if there is a flat line on a velocity time graph? | The object is moving at a constant speed |
What does a steeper slope mean on a velocity time graph? | A larger acceleration |
What does a downwards slope mean on a velocity time graph mean? | The object is decelerating |
How do you find the distance travelled on a velocity time graph? | Use the area under the graph and use the equation Speed/ Time |
How do you find out the acceleration on a velocity time graph? | Calculate the gradient of the slope (section) that you want to know |
What is terminal velocity? | When the object's weight is balanced by air resistance and there is no resultant force acting upon the object and the object reaches a steady speed. |
What is the limit of proportionality? | The point in which a spring can return to its original shape after being stretched. |
What happens to a spring after it goes past its limit of proportionality? | It cannot return back to its original shape |
What is gravitational potential energy? | The amount of energy an object has when it is held above the ground. |
What does the Open switch symbol look like? | |
What symbol is this? | Closed Switch |
What does the lamp switch look like? | |
What symbol is this? | A Cell |
What does the Diode symbol look like? | |
What does a Thermistor look like? | |
What symbol is this? | Battery |
What does a Voltmeter look like? | |
What does a Resistor look like? | |
What symbol is this? | A Fuse |
What symbol is this? | A Variable Resistor |
What does the symbol for an Ammeter look like? | |
What symbol is this? | An LDR (Light Dependant Resistor) |
What symbol is this? | A LED (Light Emitting Diode) |
What does resistance do? | Appose the flow of the current |
What are the three main wires in a plug? | Live Wire Earth Wire Neutral Wire |
Which two wires are responsible for carrying the charge to and from the mains supply? | The Live wire The Neutral wire |
What happens if the live wire comes into contact with the metal case of a plug? | If someone touches it they could get an electric shock. |
What does the earth wire do? | If the current gets too high in the live wire the earth wire will take the current away from it and because the earth wire has a low resistance causing the current to increase. |
How is the fuse made as a safety device? | If the current gets too high, it then melts the fuse wire, saving the device from exploding or electrocuting someone |
What is another safety device in circuits, what are they and how to they make the circuit safe? | Circuit breakers They are an electromagnetic switch that opens (Trips) when there is a fault in the circuit and stops it flowing. The electromagnet is connected in the series with the live wire and if the current is too large this causes the magnetic field of the electromagnet to be big enough to pull the switch contacts apart. The switch will remain open until its reset. |
What was the early 1900's model of the atom and what did it suggest the atom was like? | The plum pudding model It suggested that the atom was a positively charged fluid with electrons inside of it. |
How was the plum pudding model disproved? | by firing alpha particles (positively charged particles) at a gold leaf and observing that angles at which they got reflected they saw that a number of particles got deflected at different angles with some coming straight back on themselves, when in theory the particles should of passed straight through. |
What conclusion came from the Rutherford and Marsden scattering experiment? | That most of the atom was empty space with a small positively charged nucleus in the centre with electrons orbiting the outside. |
What is Hooke's law? | That when a weight (force) is applied to a spring, it extends and the amount it extends is proportional to the force added |
How can the spring constant be determined on a graph? | From the gradient on a force extension graph |
What can you determine with an oscilloscope? | The time taken for one cycle (the period) and frequency of the alternating current. |
What are the properties of a series circuit? | The total resistance is the sum of the resistance of each component in the circuit The current is the same at every point in the circuit The total voltage is the voltage of the cells added together The voltage is shared between each component in the circuit. |
What are the properties of a parallel circuit? | The voltage is the same across each branch The current into a junction is equal to the current going out of the junction |
What does a distance time graph show? | How an objects distance is changing over time |
What does a smooth slope on a distance time graph show? | That they object is moving at a constant speed |
What does a flat line on a distance time graph show? | That the object is stationary (not moving) |
What does a slope downward on a distance time graph show? | That the object is returning to its starting position. |
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