Gravity
Science: KS3, topic 3.5.15
Gravity
Gravity is a force. Every object that has mass will exert an attractive pull on another object. Gravity was discovered by Issac Newton. Newton wondered how and why an apple fell from a tree.
Isaac Newton
- Isaac Newton was born on the 4th January 1643 in Lincolnshire, England.
- Newton died on the 31st March 1727.
- Around 1666, Newton discovered gravity when an apple fell to the ground.
Apple Myth
- The myth states the apple hit Newton on the head.
- But there is no evidence for this.
Gravity
- All objects have a gravitational “pull” towards the centre of an object.
- Moons orbit planets due to gravity.
- Planets orbit the sun due to gravity.
Gravity's Effects
- Gravity keeps us firmly on the Earth and not floating off into space.
- You get further from a body of mass, such as a planet.
- So gravity gets weaker.
Too Much Gravity
- If gravity was too strong, we wouldn’t be able to walk.
- Our legs would be ‘stuck’ to the ground.
Test yourself on Gravity
Why does the Moon orbit the Earth?
Which are true of gravity?
A spacecraft moves further away from Earth, out into space. What happens to the pull of gravity from Earth on the spacecraft?
An apple falls straight down from a tree instead of moving sideways. Based on how gravity acts, why does this happen?