An airplane of mass 1300 kg has an engine failure when flying with an airspeed of 131 km/h at an altitude of 2900 m on a calm day. It then glides at a constant glide angle (which is the direction of flight below the horizontal) towards a safe landing at this constant speed of 131 km/h experiencing a drag force of 1300 N that opposes the direction in which the plane is moving.
Suppose the pilot instead had managed to get the airplane engine started such that he was able to apply full throttle and the airplane climbed along a straight line angled above the horizontal so that it gained altitude at a steady rate of 4.61 m/s. Assuming he was again flying with an airspeed of 131 km/h.
Determine the flight angle above the horizontal the plane is flying.
My attempt: if we draw a triangle, its hypotenuse is the thrust force, its opposite side is the force of gravity. So to find the angle we have to use this
But I can't evaluate . The correct answer has to be 7.28°. Can anyone help?