The problems are on the solar system worksheet. Try them on your own first, then compare with the answers below.
Quick answer: The solar system is the Sun with the eight planets that orbit it, held in place by the Sun's gravity. These worked answers correct the 20 problems of the grade 6 science worksheet on solar system, from planet order to daylight in Leeds: each solution shows the formula, the substitution and the final answer with its unit.
Check your answers once you have tried every problem. Pay attention to the method and to the units, because astronomy answers often use very large numbers that you must write clearly.
Level: Grade 6 science (Year 7 · Class 6) · Curriculum: MS-ESS1-2
Problem 1 Planet order
1. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.2. Earth.
Problem 2 Rotate or revolve?
1. (a) Rotation. (b) Revolution around the Sun.2. Rotation: 24 hours. Revolution: about 365 days.
Problem 3 True or false?
(a) True. (b) False: the Earth orbits the Sun, and the Sun only seems to move because the Earth spins. (c) True. Only statement (b) is false.Problem 4 Gravity and orbits
1. Gravity from the Sun.2. The planet would fly off in a straight line in space.
Problem 5 Reading the planet table
1. Mars.2. More: Neptune takes 165 years and Saturn takes 29.5 years.
Problem 6 What causes seasons?
1. The tilt of the axis, 23.5°.2. Summer in the north.
Problem 7 Time zones
1. 360° ÷ 24 h = 15° per hour. 75° ÷ 15° per hour = 5 hours.2. The east is ahead: 10:00 + 5 h = 15:00.
Problem 8 Sunrise and sunset
1. A faces the Sun: midday. C is opposite: midnight.2. The Earth spins counter-clockwise, so A moves toward D and enters darkness there: D is sunset. A place at C moves toward B and enters light: B is sunrise.
Problem 9 Light from the Sun
1. 150 000 000 km = 1.5 × 10⁸ km.2. t = d ÷ v = 150 000 000 ÷ 300 000 = 500 s. 500 ÷ 60 = 8.33 min. 500 s, about 8.3 minutes.
Problem 10 Years on Venus
1. 900 ÷ 225 = 4 Venus years.2. 900 ÷ 365 = 2.5 Earth years (2.47 to two decimal places).
Problem 11 Which season?
1. At P, the north leans toward the Sun, so sunlight is more direct and days are longer: summer in the north.2. Winter in the south, because the south leans away from the Sun.
Problem 12 Spinning at the equator
v = d ÷ t = 40 000 km ÷ 24 h = 1666.7 km/h. About 1700 km/h.Problem 13 Weight on other worlds
Earth: 50 × 9.8 = 490 N. Mars: 50 × 3.7 = 185 N. Difference: 490 − 185 = 305 N. Her mass stays 50 kg.Problem 14 Distance myth
The Earth is closer in January (147 million km) than in July (152 million km), yet July is not warmer in the north. The difference is 5 million km. The cause is the tilt, not the distance.Problem 15 Age in Mars years
3650 ÷ 687 = 5.31. About 5.3 Mars years.Problem 16 Orbital speed of Earth
1. 2π × 150 000 000 km = 942 477 796 km, about 9.42 × 10⁸ km.2. v = 942 477 796 ÷ 8760 = 107 589 km/h. Divide by 3600: 29.9 km/s. About 1.08 × 10⁵ km/h or 29.9 km/s.
Problem 17 Slow Jupiter
1. 2π × 778 000 000 = 4.888 × 10⁹ km. Time: 4333 × 24 = 103 992 h. Speed: 4.888 × 10⁹ ÷ 103 992 = 47 006 km/h. About 4.7 × 10⁴ km/h.2. 47 006 ÷ 107 589 = 0.44. Jupiter moves at 44 % of Earth’s speed, so planets farther out orbit more slowly.
Problem 18 Straight line or curve?
1. The planet moves sideways fast, so as gravity pulls it inward, it keeps missing the Sun and bends into a curve: the sideways motion balances the fall.2. A stronger pull would bend the path more, so the planet would spiral closer to the Sun: its orbit would shrink.
Problem 19 Equator and Leeds
In June the north leans toward the Sun, so a northern place such as Leeds spends more than half its daily circle in sunlight. The equator is always cut in half by the day-night line, giving about 12 h every day. The tilt makes daylight vary with latitude, but at the equator it stays near 12 h.Problem 20 Daylight in Leeds
1. 16.7 − 7.6 = 9.1 hours.2. 16.7 ÷ 24 × 100 = 69.6 %.
3. 21 December is at the start of northern winter; the north leans away from the Sun, so the Sun is low and the days are short.
