Asian Physics Olympiad · Year 2013

Problems

Problem 1An object is launched from level ground with initial speed $v_0$ at angle $\theta$ above the horizontal. Neglect air resistance and take constant gravitational acceleration $g$ . Find the flight time, range, and maximum height. 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 2Two resistors $R_1$ and $R_2$ are connected in parallel to an ideal voltage source $V$ . Find the equivalent resistance, current through each resistor, and total power supplied by the source. 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 3A sound source of frequency $f_s$ moves directly toward a stationary listener at speed $v_s<c_s$ , where $c_s$ is the speed of sound in air. Find the observed frequency. 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