Ignoring air resistance, the horizontal range of a projectile is maximum when the angle of projection with the horizontal is:

Consider the following statements regarding motion in a plane: Statement I: For an object moving in a plane, acceleration can be non-zero even if speed is constant, but acceleration cannot be zero if velocity is changing. Statement II: The velocity of a moving object may change direction without changing its magnitude. Select the correct answer using the options below:

An aeroplane is flying horizontally with a velocity of 600 km/hr at a height of 1960 m. When it is vertically above point 'P' on the ground, a body is dropped from it. The body hits the ground at point 'Q'. The distance 'PQ' is (take g = 9.8 m/s2):