Prelims 2015 · Geography · Question 70
Tides occur in the oceans and seas due to which among the following?
- Gravitational force of the Sun
- Gravitational force of the Moon
- Centrifugal force of the Earth
Select the correct answer using the code given below.
Answer
1, 2 and 3
1. Gravitational force of the Sun — Correct. The Sun’s gravity also pulls ocean water and contributes to tides, though less strongly than the Moon.
2. Gravitational force of the Moon — Correct. The Moon is the main cause of tides because its gravitational pull on Earth’s oceans is strongest.
3. Centrifugal force of the Earth — Correct. In the Earth–Moon system, a centrifugal force arises due to their revolution around the common barycentre; along with lunar gravity, it helps produce the two tidal bulges.
Hence, all three are involved in causing tides.