The Earth's pull
Gravity.
Thrown up
You throw a ball high into the air.
What happens to it at last?
What this lesson covers
The idea
The force with which the Earth attracts objects towards itself is the gravitational force, or gravity; it acts without contact and is always attractive, unlike magnetic or electrostatic force.
Thrown up
You throw a ball high into the air.
What happens to it at last?
- It comes back down
- It stays in the air
- It flies away
Let go
Pick each object and press Let go.
Always down
Every object fell towards the Earth, so the Earth attracts them. This force acts without touching and is always attractive.
The force with which the Earth attracts objects towards itself is the gravitational force, or gravity. It acts without contact, so it is a non-contact force. It is always attractive, unlike magnetic or electrostatic force, which can also repel.
Notes
The gravitational force, or gravity, is the force with which the Earth attracts objects towards itself. It is a non-contact force and is always attractive.
Check yourself
The Earth's pull on objects is called …
Gravitational force is always …
Which of these can be either attractive or repulsive?
Gravity is a …
- gravitational force — correct. Yes!
- magnetic force. Magnetic force comes from magnets.
- friction. Friction needs two surfaces in contact. Gravity acts from a distance.
- repulsive. Gravity is always attractive.
- attractive — correct. Yes!
- attractive or repulsive, like magnets. Unlike magnetic force, gravity is always attractive.
- Gravitational force. Gravity is always attractive.
- The Earth's pull on an apple. That is gravity, which is always attractive.
- Magnetic force — correct. Yes!
- non-contact force — correct. Yes!
- contact force. Gravity acts without contact.
- muscular force. Gravity does not come from muscles.