Question

A particle of mass m slides on the surface of a smooth bowl with equation p2 = az in cylindrical polar coordinates p, 0 and z, with the z-axis pointed

vertically upwards, where a is a positive constant. (i) Briefly explain why \frac{1}{2} m\left(\dot{\rho}^{2}+\rho^{2} \dot{\theta}^{2}+\dot{z}^{2}\right)+m g z=\text { constant } \rho^{2} \dot{\theta}=\text { constant. } ) The particle is initially at height a above the lowest point of the bowl, moving horizontally along the bowl with speed pé = v. Show that \dot{\rho}^{2}+\rho^{2} \dot{\theta}^{2}+\dot{z}^{2}+2 g z=v^{2}+2 g a \rho^{2} \dot{\theta}=a v Hence deduce that \left(1+\frac{a}{4 z}\right) \ddot{z}-\frac{a \dot{z}^{2}}{8 z^{2}}-\frac{a v^{2}}{2 z^{2}}+g=0 ) If v² > 2ag will the particle rise or fall initially? What is the particle's maximum height in the bowl?

Question image 1Question image 2Question image 3Question image 4Question image 5Question image 6Question image 7Question image 8Question image 9Question image 10