Motion of particles Flashcards
what do particle accelerators do
they help scientists find out more about more about the subatomic particles that the world is made up of.
Discuss reasons for collaborative, international research into big scientific questions, including particle physics
it shares the cost of the project and it allows scientists to share knowledge and expertise
Explain how for motion in a circle there must be a resultant force
for an object to move in a circular path there must be a force acting on it towards the centre of the path - this is called the centripetal force. in a cyclatron this centripetal force is caused by a strong magnetic field acting on the changed particles
Explain how particle accelerators called cyclotrons cause charged particles to move in a circular or spiral path, due to a magnetic field
electrons are fired into the centre of one of the D-shaped enclosures, and a strong magnetic field deflects there electrons so that they follow the curved path shown. as they cross the gap form one D electrode to the other a large voltage makes them accelerate. eventually the electrons emerge at very high speed and very large kinetic energy.
Demonstrate an understanding that certain stable elements can be bombarded with proton radiation to change them into radioactive isotopes
stable isotopes can be made radioactive by using a cyclotron to fire high energy particles at their nuclei. e.g. xenon gas can be bombarded with protons to make the radioactive isotope iodine-131.
Describe the use of particle accelerators (cyclotrons) to produce radioactive isotopes for medical purposes
xenon gas can be bombarded with protons to make the radioactive isotope iodine-131. this iodine is used in the treatment and diagnosis of conditions affecting the thyroid land
what happens to energy in inelastic collisions
the kinetic energy is greater before the collision and less after the collision. momentum is conserved in a inelastic collision
what happens to energy in elastic collisions
the kinetic energy is the same before and after the collision. momentum is also conserved
Analyse collisions in one dimension in terms of momentum and kinetic energy
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Carry out calculations using momentum conservation for a two-body collision (in one dimension only)
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Carry out calculations using conservation of kinetic
energy for a two-body elastic collision (in one dimension
only)
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how can gamma rays be produced
gamma rays can be produced by the annihilation of an electron and a positron
Apply the idea of conservation of mass energy for positron electron annihilation
a in a qualitative way (calculations involving E 5 mc2 will not be required)
b in a quantitive way using the equation E 5 mc2
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Apply conservation of momentum and charge to positron
electron annihilation
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Explain the use of radio isotopes in PET scanners to produce gamma rays
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