A person from the top of a hill observes a vehicle moving towards him at a uniform speed. It takes 10 minutes for the angle of depression to change from 45 ° to 60 °. After this the time required by the vehicle to reach the bottom of the hill is 

From an observation tower ‘h’ meter above the level of river, the angle of depression of a point on the near shore is A^° and that of a point directly on the far shore is B^°. Find the width of the river.

A kite is flying at a height of 50m. If the length of string is 100m then the inclination of string to the horizontal ground in degree measures is:

The angle of elevation of a tower from a distance 50 m from its foot is 30°. The height of the tower is 

The angle of elevation of the top of a tower from two points A and B lying on the horizontal through the foot of the tower are 159 and 30° respectively. If A and B are on the same side of the tower and AB = 48 meter, then the height of the tower is; 

The angles of elevation of top and bottom of flag kept on a flag post from 30 metres distance, are 45 ° and 30 ° respectively. Height of the flag is [ taking 13 = 1.732) 

A telegraph post is bent at a point above the ground. Its top just touches the ground at a distance of 8√3 m from its feet and makes an angle of 30 ° with the horizontal. The height (in metre) of the post is 

A straight tree breaks due to storm and the broken part bends so that the top of the tree touches the ground making an angle of 30 ° with the ground. The distance from the foot of the tree to the point, where the top touches the ground is 10m. Find the total height of the tree