Find the distance from the eye at which a coin must be placed so as just to hide the full moon.The diameter of coin being 2 cm and the diamter of the moon makes an angle 31'at the eye of the observer.

The distance of earth from the moon is 3,85,000 km and the moon 's diameter subtends an angle of 31' at the eye of the obsever. Find the diameter of the moon.

Assuming the distance of the earth from the moon to be 38,400 km and the angle subtended by the moon at the eye of a person on the earth to be 31’, find the diameter of the moon.

Assuming the distance of the sun from the observer to be 9,30,00000 miles and the angle subtended by the diameter of the sun at the eye of the observer to be 32' , find the diameter of the sun.

The radius of the earth 6400 km and moon's distance from the earth is 60 times , the radius of earth , if the radius of the moon subtends 16' angle at the centre of the earth ,find the diameter of the moon.

If the angular diameter of the moon be 30, how far from the eye a coin of diameter 2. 2c m be kept to hide the moon?

If the diameter of the sun subtends an angle of 32' at the eye of the observer and the diameter of the moon 30' and if the distance of the sun be 360 times that of the moon , find the ratio of the diameter of the sun of that of the moon.

The diameter of the moon is about 2160 km . When the moon's distance from a concave mirror is 43.2 xx 10^(4) km , an image of diameter 1.5 cm of the moon is formed. What is the radius of the mirror?

A man is moving away from a tower 41.6 m high at the rate of 2 m/sec. Find the rate at which the angle of elevation of the top of tower is changing, when he is at a distance of 30m from the foot of the tower. Assume that the eye level of the man is 1.6m from the ground.