Asian Physics Olympiad · Year 2014

Problems

Problem 1A mass $m$ is released from rest at height $h$ above the uncompressed top of a vertical spring of stiffness $k$ . Neglect resistance and take constant $g$ . Find the maximum compression $x$ . Assume the string, pulley, electrical source, or optical apparatus is ideal as stated, and neglect any effect not specified. State a clear sign convention, identify the physical Keep one model and sign convention throughout. Reuse each intermediate result with the same convention, then check that the answer has the required physical dimensions. (a) Set up the physical relation. (b) Find an intermediate quantity. (c) Obtain the answer and check its conditions and units.Solutions: 1
Problem 2A monatomic ideal gas containing $n$ moles is heated at constant volume from temperature $T_1$ to $T_2$ . Given the gas constant $R$ , find the heat absorbed and the change in internal energy. Assume the string, pulley, electrical source, or optical apparatus is ideal as stated, and neglect any effect not specified. State a clear sign convention, identify the physical Keep one model and sign convention throughout. Reuse each intermediate result with the same convention, then check that the answer has the required physical dimensions. (a) Set up the physical relation. (b) Find an intermediate quantity. (c) Obtain the answer and check its conditions and units.Solutions: 1
Problem 3Monochromatic light of wavelength $\lambda$ passes through two narrow slits separated by $d$ onto a screen distance $L$ away, with $L\gg d$ . Find the fringe spacing $i$ and position of bright fringe order $m$ from the central maximum, using the small-angle approximation. Assume the string, pulley, electrical source, or optical apparatus is ideal as stated, and neglect any effect not specified. State a clear sign convention, identify the physical Keep one model and sign convention throughout. Reuse each intermediate result with the same convention, then check that the answer has the required physical dimensions. (a) Set up the physical relation. (b) Find an intermediate quantity. (c) Obtain the answer and check its conditions and units.Solutions: 1