What causes the tides

Grade 6 Science Worksheet - Building Confidence

Circle the best answer.

1. Read this first

   Table (example data)

   Water level at a dock. 6 a.m.: 0.9 m. 9 a.m.: 1.6 m. 12 noon: 2.2 m. 3 p.m.: 1.4 m. 6 p.m.: 0.6 m.

2. 1.

   Esme reads a dock's water-level table. At which time was it high tide?

   • 12 noon, when the water was at 2.2 m
   • 6 p.m., when the water was at 0.6 m
   • 9 a.m., when the water was at 1.6 m
   • 6 a.m., when the water was at 0.9 m

3. Table (example data)

   Water level in a harbor. 7 a.m.: 1.4 m. 10 a.m.: 0.8 m. 1 p.m.: 0.3 m. 4 p.m.: 1.0 m. 7 p.m.: 1.9 m.

4. 2.

   Jun reads a harbor's water-level table. At which time was it low tide?

   • 7 a.m., when the water was at 1.4 m
   • 1 p.m., when the water was at 0.3 m
   • 7 p.m., when the water was at 1.9 m
   • 10 a.m., when the water was at 0.8 m

5. Table (example data)

   Water level at a boat ramp. 8 a.m.: 1.5 m. 11 a.m.: 0.9 m. 2 p.m.: 0.2 m. 5 p.m.: 1.0 m. 8 p.m.: 1.8 m.

6. 3.

   Luz reads a boat ramp's water-level table. How low was the water at low tide?

   • 1.5 m, the reading at 8 a.m.
   • 0.2 m, the reading at 2 p.m.
   • 1.8 m, the reading at 8 p.m.
   • 0.9 m, the reading at 11 a.m.
7. 4.

   Milo reads a class blog about the ocean. What mostly causes the tides?

   • The Moon's gravity pulling on the ocean, with a smaller pull from the Sun.
   • Rain and rivers adding water to the ocean, which later drains back out.
   • The Moon's light warming the ocean so that the water swells upward.
   • Strong winds pushing the ocean water toward the coast again and again each day.
8. 5.

   Noah checks a harbor's tide table and finds the times are the same on calm days and stormy days. What does that suggest?

   • The Sun causes most tides, because the Sun is larger than the Moon.
   • Storms still cause the tides, but their effect is too small to notice.
   • Rivers cause the tides, since their flow follows the same schedule.
   • Tides come from something steady, like the Moon's gravity.
9. 6.

   Printed tide tables list tides a year ahead. Pia asks why people can do that. What is the best reason?

   • The Moon and Earth move in regular patterns, so tides repeat.
   • The Moon's light changes on a schedule, so the water swells on schedule.
   • Rivers fill and empty the ocean on a fixed schedule through the year.
   • Winds blow on a fixed schedule, so the winds can be planned ahead.
10. 7.

    Ren says the Sun, not the Moon, has the biggest effect on tides. What is the best correction?

    • Neither one, because tides come from winds that blow over the whole ocean.
    • The Moon has the bigger effect, and the Sun adds a smaller one.
    • The Moon's light, not the Sun's, is what lifts the water into tides.
    • That is right, because the Sun is much larger than the Moon is.
11. 8.

    High tide at Tala's dock is at 6:00 a.m. The next high tide comes about 12 hours 25 minutes later. When is it?

    • 6:00 p.m.
    • 6:25 p.m.
    • 5:35 p.m.
    • 6:50 p.m.
12. 9.

    High tide at Zee's pier is at 9:30 a.m. The next high tide comes about 12 hours 25 minutes later. When is it?

    • 9:05 p.m.
    • 10:20 p.m.
    • 9:30 p.m.
    • 9:55 p.m.
13. 10.

    High tide at Ari's beach is at 2:00 p.m. Low tide comes about 6 hours 12 minutes later. When is low tide?

    • 8:50 p.m.
    • 8:00 p.m.
    • 8:12 p.m.
    • 7:48 a.m.