If an object is projected at an angle, the vertical and horizontal motion can still be treated separately by considering the components of the velocity in each plane. In the vertical plane, the initial velocity is usinθ (upwards) and the acceleration is 9.8ms^-2 (downwards). As both are vectors, if a positive value is assigned to the initial velocity, the acceleration and the downward velocities and displacements will have negative values. Neglecting air resistance, the horizontal component of the initial velocity ucosθ, will remain constant throughout the motion