Push and Pull
Forces are pushes or pulls. They are measured in newtons.
Unbalanced forces change the way something is moving.
The mass of an object is how much matter it contains. The weight of an object is the force caused by gravity pulling down on the mass.
Unbalanced forces change the way something is moving.
The mass of an object is how much matter it contains. The weight of an object is the force caused by gravity pulling down on the mass.
Gravity
The force that makes things fall to the ground on Earth (and other planets) is called gravity.
Gravity also holds Earth and the other planets in their orbits around the Sun.
The force of gravity also exists on the Moon but it is not as strong as it is on Earth. This is because the Moon is much smaller than our planet.
Gravity also holds Earth and the other planets in their orbits around the Sun.
The force of gravity also exists on the Moon but it is not as strong as it is on Earth. This is because the Moon is much smaller than our planet.
Mass and Weight
The mass of an object is how much matter it contains. It is measured in grams (g) or kilograms (kg) but is NOT a force.
The weight of an object is the force caused by gravity pulling down on the mass of an object. It is measured in newtons (N).
Measuring weightWeight is measured using a forcemeter. The bigger the weight attached to the forcemeter, the more the spring inside the forcemeter stretches.
The weight of an object is the force caused by gravity pulling down on the mass of an object. It is measured in newtons (N).
Measuring weightWeight is measured using a forcemeter. The bigger the weight attached to the forcemeter, the more the spring inside the forcemeter stretches.
Balanced forces
Forces are just pushes and pulls in a particular direction.
Forces are shown by arrows in diagrams. The direction of the arrow shows the direction in which the force is acting. The bigger the arrow, the bigger the force.
If two forces are balanced, it means the forces are the same size but are acting in opposite directions.
Balanced forces do not change motionIf two balanced forces are acting on an object, that object will not change its motion.
Forces are shown by arrows in diagrams. The direction of the arrow shows the direction in which the force is acting. The bigger the arrow, the bigger the force.
If two forces are balanced, it means the forces are the same size but are acting in opposite directions.
Balanced forces do not change motionIf two balanced forces are acting on an object, that object will not change its motion.
- If it is still, it will stay still.
- If it is moving, it will continue moving, in the same direction and at the same speed.
Unbalanced forces
Unbalanced forces do change the way something is moving.
Unbalanced forces can make objects start to move, speed up, slow down, or change direction.
Unbalanced forces can make objects start to move, speed up, slow down, or change direction.
Springs
When a spring is stretched or squashed, it creates a force in the opposite direction because the spring tries to get back to its original shape.
For example, when you squash a spring downwards on a table, you will feel a push upwards on your hand. The more you squash the spring, the bigger the push you will feel.
For example, when you squash a spring downwards on a table, you will feel a push upwards on your hand. The more you squash the spring, the bigger the push you will feel.