Question : The angle of elevation of an aeroplane from a point on the ground is 45°. After flying for 15 seconds, the elevation changes to 30°. If the aeroplane is flying at a height of 2500 metres, then the speed of the aeroplane in km/h is:

Option 1: $600$

Option 2: $600(\sqrt{3}+1)$

Option 3: $600\sqrt{3}$

Option 4: $600(\sqrt{3}–1)$

Question : The angle of elevation of an aeroplane from a point on the ground is 60°. After flying for 30 seconds, the angle of elevation changes to 30°. If the aeroplane is flying at a height of 4500 metres, then what is the speed (in m/s) of an aeroplane?

Option 1: $50\sqrt3$

Option 2: $100\sqrt3$

Option 3: $200\sqrt3$

Option 4: $300\sqrt3$