重力把物体往下拉
Gravity Pulls Things Down
理解重力是一种把物体拉向地心的力；无论站在地球球面上的哪个位置，“向下”都指向地心；重力还使月球绕地球运行、使行星绕太阳运行。
Understand gravity as a force that pulls objects towards the centre of the Earth, that 'down' means towards Earth’s centre regardless of where you stand on the sphere, and that gravity keeps the Moon orbiting Earth and planets orbiting the Sun
学习证据 / Evidence
- 将重力定义为一个把物体拉向地心的力
- 解释“向下”指向地心，因此地球上相对两边的人都会感到被“向下”拉
- 说明重力使月球绕地球运行，使行星绕太阳运行
- Define gravity as a pulling force that attracts objects towards the centre of the Earth
- Explain that 'down' points towards Earth's centre, so people on opposite sides of the globe both feel pulled 'down'
- State that gravity keeps the Moon orbiting Earth and planets orbiting the Sun
评估问题 / Assessment
{{name}}能解释为什么物体会向下落，以及重力就是让月球绕着地球转的同一个力吗？
Can {{name}} explain why things fall 'down' and that gravity is the same force keeping the Moon going around the Earth?