If I stand on the beach and watch a ship sailing directly away from me, when the ship disappears below the horizon what would the distance from shore to the point of disappearance be? Assume the ship smokestack at 30 metres above sea level. This an actual case, as I am at present at Maroochydore and ships are coming and going to the Caloundra Channel.
bucolic3401 said:
If I stand on the beach and watch a ship sailing directly away from me, when the ship disappears below the horizon what would the distance from shore to the point of disappearance be? Assume the ship smokestack at 30 metres above sea level. This an actual case, as I am at present at Maroochydore and ships are coming and going to the Caloundra Channel.
about 4.6 leagues ottomh
stumpy_seahorse said:
bucolic3401 said:
If I stand on the beach and watch a ship sailing directly away from me, when the ship disappears below the horizon what would the distance from shore to the point of disappearance be? Assume the ship smokestack at 30 metres above sea level. This an actual case, as I am at present at Maroochydore and ships are coming and going to the Caloundra Channel.
about 4.6 leagues ottomh
http://en.wikipedia.org/wiki/Horizon
Distance to the horizon
Ignoring the effect of atmospheric refraction, distance to the horizon from an observer close to the Earth’s surface is about
where d is in kilometres and h is height above ground level in metres.
Examples: For an observer standing on the ground with h = 1.70 metres (5 ft 7 in) (average eye-level height), the horizon is at a distance of 4.7 kilometres (2.9 mi). For an observer standing on the ground with h = 2 metres (6 ft 7 in), the horizon is at a distance of 5 kilometres (3.1 mi). For an observer standing on a hill or tower of 100 metres (330 ft) in height, the horizon is at a distance of 36 kilometres (22 mi). For an observer standing at the top of the Burj Khalifa (828 metres (2,717 ft) in height), the horizon is at a distance of 103 kilometres (64 mi). For an observer atop Mount Everest (8,848 metres (29,029 ft) altitude), the horizon is at a distance of 336 kilometres (209 mi).
transition said:
http://en.wikipedia.org/wiki/Horizon
Distance to the horizonIgnoring the effect of atmospheric refraction, distance to the horizon from an observer close to the Earth’s surface is about
where d is in kilometres and h is height above ground level in metres.
Examples: For an observer standing on the ground with h = 1.70 metres (5 ft 7 in) (average eye-level height), the horizon is at a distance of 4.7 kilometres (2.9 mi). For an observer standing on the ground with h = 2 metres (6 ft 7 in), the horizon is at a distance of 5 kilometres (3.1 mi). For an observer standing on a hill or tower of 100 metres (330 ft) in height, the horizon is at a distance of 36 kilometres (22 mi). For an observer standing at the top of the Burj Khalifa (828 metres (2,717 ft) in height), the horizon is at a distance of 103 kilometres (64 mi). For an observer atop Mount Everest (8,848 metres (29,029 ft) altitude), the horizon is at a distance of 336 kilometres (209 mi).
About 19km till the top of the ship disappears.
Use Pythagoras to work out the distance.
Radius of the Earth is 6371,000 m according to Wiki.
Assume your are 1.7 m above the sea level and the top of the ship is 30 m, you have one length of 6,371,001.7 m and hypotenuse of 6,371,030 m.
stumpy_seahorse said:
bucolic3401 said:
If I stand on the beach and watch a ship sailing directly away from me, when the ship disappears below the horizon what would the distance from shore to the point of disappearance be? Assume the ship smokestack at 30 metres above sea level. This an actual case, as I am at present at Maroochydore and ships are coming and going to the Caloundra Channel.
about 4.6 leagues ottomh
sorry, hit the wrong key, should be 3.6
18,989 m approx from your eye to the top of the smoke stack as it dips below the horizon.