Physic Labs

Asian Physics Olympiad · Year 2001

Problems

  1. Problem 1A ball is launched horizontally at v0=20 m/sv_0=20\,\mathrm{m/s} from a cliff of height h=45 mh=45\,\mathrm m. Neglect air resistance and take g=10 m/s2g=10\,\mathrm{m/s^2}. Find the flight time, horizontal range, and impact speed. Treat the stated idealizations as exact: objects may be treated as point-like or uniform where appropriate, and any external effect not specified is neglected. (a) Establish the governing physical relation and state the sign convention and boundary conditions. (b) Evaluate the requested quantities from the supplied data with consistent units. (c) Check dimensions and explain the physical meaning of the resulting sign or limiting case.Solutions: 1
  2. Problem 2A capacitor C=4 μFC=4\,\mu\mathrm F is charged to V0=12 VV_0=12\,\mathrm V and then connected across a resistor R=3 kΩR=3\,\mathrm{k\Omega}. Find its charge and current during discharge, the time constant, and initial stored energy. Treat the stated idealizations as exact: objects may be treated as point-like or uniform where appropriate, and any external effect not specified is neglected. (a) Establish the governing physical relation and state the sign convention and boundary conditions. (b) Evaluate the requested quantities from the supplied data with consistent units. (c) Check dimensions and explain the physical meaning of the resulting sign or limiting case.Solutions: 1
  3. Problem 3An object of height h=1.0 mh=1.0\,\mathrm m stands a distance dd from a vertical plane mirror. A ray from its top strikes the mirror at an incidence angle of 30∘30^\circ to the normal. Find the image position and size, and the reflection angle. Treat the stated idealizations as exact: objects may be treated as point-like or uniform where appropriate, and any external effect not specified is neglected. (a) Establish the governing physical relation and state the sign convention and boundary conditions. (b) Evaluate the requested quantities from the supplied data with consistent units. (c) Check dimensions and explain the physical meaning of the resulting sign or limiting case.Solutions: 1