1. The problem statement, all variables and given/known data Suppose a solid body approaches a sphere of radius one and height z, how do I calculate the angle ##\theta## at which the body bounces off the sphere? An image is attached: 2. Relevant equations Angle of incidence, reflection and velocity 3. The attempt at a solution I was told that the following but I still do not know how to apply it correct. "Break down the velocity vector of the solid body into two components: one is tangential to the sphere, another one points to the centre of the sphere. Reverse the direction of the central component and add the two component together and you will have the bounce off velocity vector. The angle between incident and reflected angle is what you need. Divide it by two and you will have the answer."