The angle of elevation of an aeroplane from a point on the ground is . After flying for 30 seconds, the angle of elevation changes to . If the aeroplane is flying at a height of 4500 metre, then what is the speed (in m/s) of aeroplane?
A kite is flying in the sky. The length of string between a point on the ground and kite is 420 metre. The angle of elevation of string with the ground is . Assuming that there is no slack in the string, then what is the height (in metres) of the kite?
A balloon leaves from a point P rises ay a unifom speed. After 6 minutes, an observer situated at a distance of metres from point P observes that angle of elevation of balloon is . Assume that point of observation and point P are on the same level. What is the speed (in m/s) of the balloon?