What is Gravity?
You are visiting the Science For All site
Lesson – What is gravity?
Aims:
1. gravity is an attractive force
2. mass creates gravity, gravity creates weight
3. idea of gravity related to observation
Outcomes:
Can state that objects dropped anywhere on the Earth will fall and use the idea of gravity to explain a range of observations.
Needs:
Assorted masses, globe, tennis ball, Science to 16,
Links:
From Unit 7K, difference between mass and weight, gravity is a force of attraction, pulls towards the centre of bodies, and greater masses exert greater attraction.
Intro (5 min)
Video clip of weightlessness, played in silence. Pupils to suggest after seeing the clip what was going on and why the astronauts were behaving as they were.
Discussion (10 min)
Pupils state their knowledge and understanding of gravity. Use globe to check they understand that gravity will pull a ball towards its surface. Lead to idea that gravity pulls towards the centre of objects (aims 1+3) Check they know Newton came up with the idea of gravity and compare it with Greeks ideas.
DART (25 min)
Use information and question sheets to review the ideas of mass and weight. Cut the information sheet into sections, each pupil in the group has one piece of information . The group scribe then has to ask the questions and the pupil with the appropriate section furnishes the answer. (aims 1+2). Remember to focus on the units of weight and mass. Go over answers about 20 min into the activity.
Extension: Pupils work out the answers to some questions based on text book pages.
Practical (10 min)
Measure the weight of some masses, need to choose the appropriate Newton meter. Work out the relationship between the two. (aims 1+3)
Close (5 min)
Determine the relationship between mass and weight. Pupils to state one thing that they have learnt in the lesson.
