Edexcel International GCSE Physics8b Motion in the universe Checklist

Papers 1 and 2

• I know that:•the universe is a large collection of billions of galaxies•a galaxy is a large collection of billions of stars•our solar system is in the Milky Way galaxy
• I understand why the gravitational field strength, g, varies, and I know that it is different on other planets and on the Moon from on the Earth.
• I can explain that gravitational force:•causes moons to orbit planets•causes the planets to orbit the Sun•causes artificial satellites to orbit the Earth•causes comets to orbit the Sun
• I can describe how the orbits of comets, moons and planets differ.
• I can use the relationship between orbital speed, orbital radius and time period: orbital speed = (2 × π × orbital radius) / time period, v = (2 × π × r) / T