1. The problem statement, all variables and given/known data As shown in the figure below, small object A is projected upward along a smooth slope forming angle α with the horizontal plane, with initial speed v0 in the direction of angle θ from the horizontal within the slope’s plane. The object continues to travel along the surface of the slope. Let us denote as h the maximum height that A attains on the slope, where height is measured vertically from A’s starting point. Find v0 2. Relevant equations projectile motion 3. The attempt at a solution I interpret the question as projectile motion with total angle (α + θ) with respect to horizontal plane. At maximum height, vertical speed is zero, so: vy2 = voy2 - 2gh v0 = √(2gh) / (sin (α + θ)) But the answer is v0 = √(2gh) / (sin θ) Do I interpret the question wrongly? Or there is mistake in my working?