Most coastlines experience two high tides and two low tides each day, a rhythm that puzzled thinkers for centuries. The explanation is not that the Moon simply pulls the sea towards it. Because the Moon’s gravity weakens with distance, the near side of the Earth is pulled more strongly than the Earth’s centre, and the centre more strongly than the far side. The difference stretches the oceans into two bulges, one facing the Moon and one on the opposite side. As the Earth rotates beneath these bulges, a given harbour passes through both of them in a lunar day. A lunar day lasts about 24 hours and 50 minutes, because the Moon moves along its orbit in the same direction in which the Earth spins; as a result, high tide arrives roughly fifty minutes later each day. The Sun exerts a similar, though weaker, effect. When the Sun, Earth and Moon are aligned, at new and full moon, the two effects reinforce each other and produce spring tides, with an unusually large difference between high and low water. When the Moon is at a right angle to the Sun, at the first and last quarters, the effects partly cancel, and the resulting neap tides are modest. Local geography complicates this picture: in a narrow, funnel-shaped bay, the incoming water can be squeezed so that the range is far greater than in the open ocean.
According to the text, spring tides occur when
Дұрыс жауабы мен түсіндірмесі
Жауабы: the Sun, Earth and Moon lie in a line
Жаңа және толған айда Күн, Жер, Ай бір сызықта; әсерлері қосылып, ең үлкен айырма береді. “Spring” маусымға қатысы жоқ.
«Мәтінмен жұмыс» тақырыбынан тағы
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