Flashcards
Leaving Cert Physics 2013
Cards in this deck (11)
- 1What is the shortest stopping time for a car which is travelling at \[16m s^{-1}\] and has a maximum deceleration of \[2.5 m s^{-2}\] ?\[v = u + at\] / \[s = ut + \frac{1}{2}at^2\] / \[v^2 = u^2 +2as\]
\[t = 6.4 s\] - 2State the law of conservation of momentummomentum before = momentum after in a closed system / provided no external forces act
- 3Explain why heat does not travel through solids by means of convection.the particles cannot move (freely)
- 4Storage heaters are frequently used to heat buildings. State the principle that underlies the operation of an electrical storage heater.large heat capacity heated when electricity is inexpensive (off peak) / store a large quantity of energy /
release energy slowly (during the day) - 5If a diamond has a refractive index of 2.42, what is the speed of light in the diamond?\[n = \frac{c_1}{c_2}\]
\[c_2 = \frac{3*10^8}{2.42} = 1.24 * 10^8 m s^{-1}\] - 6Define the volt.potential difference (between two points)
if 1 J (of work) is needed to move 1 C (from one point to the other) - 7A positively charged rod is brought near to a neutral, conducting sphere that is on top of an insulating stand. How would a student charge the sphere negatively by induction?earth the sphere (stated or implied) 4
remove earth (connection) and then remove rod - 8Explain what is meant by the statement: “Zinc has a threshold frequency of \[1.04 × 10^{15}\] Hz”.below this frequency
e.m.r. /photons will not cause emission of electrons (from zinc surface) - 9Give one benefit of switching from fossil fuels to nuclear power for the generation of electricity. Explain your answermore energy per kg / less carbon dioxide produced / production of useful radioisotopes etc.
explanation - 10Give an expression for the minimum frequency of a photon that can form an electron and a positron by pair production.\[(f=) \frac{2m_e c^2}{h}\]
- 11What event inside an LED causes the release of a photon?electron combines with (positive) hole
Information
- Description
- Questions and Answers from the 2013 Leaving Certificate Physics Higher Level Exam.
- Created by
- cian.buckley+1
- Views
- 765
- Tags
- Rating