NEET Physics Question - Kinematics - Projectile from Height

Time to fall: t = 2 h / g = 90 / 10 = 3 t = \sqrt{2h/g} = \sqrt{90/10} = 3 &nbsp; s
Vertical velocity: v y = g t = 10 × 3 = 30 v_y = gt = 10 \times 3 = 30 &nbsp; m/s
Resultant velocity: v = v x 2 + v y 2 = 40 2 + 30 2 = 50 v = \sqrt{v_x^2 + v_y^2} = \sqrt{40^2 + 30^2} = 50 &nbsp; m/s

An object is projected horizontally from a 45 m high cliff with a speed of 40 m/s. With what speed will it strike the ground? (Take g=10 m/s²)

20 m/s

30 m/s