In the physics laboratory a glider is released from rest on

In the physics laboratory, a glider is released from rest on a frictionless air track inclined at an angle. If the glider has gained a speed of 21.0 cm/s in traveling 60.0 cm from the starting point, what was the angle of inclination of the track? This is all they give, there is no other info

Solution

According to the consevation of energy

       ( 1/ 2) m v ² = m g h

                     h = v ² / 2 g

                         = ( 0.21 m/s)² / 2 ( 9.8 m/s² )

   = 0.00225 m

angle of incline is

sin ( theta ) = 0.00225 m / 0.6         

   theta = 0.214 degrees