Forces Flashcards
Describe everyday situations where forces are balanced and unbalanced.
Balanced forces are equal in magnitude opposite in direction
Unbalanced forces are not equal in magnitude or opposite in direction
Example, when you are riding a bike there are 4 forces acting on you, and they are balanced, gravity is pulling you down, ground force is pulling you up, friction is slowing you down, driving force is speeding you up.
Forces can also be unbalanced while riding a bike, when you hit the brakes friction increases and overcomes the driving force.
What is inertia
Inertia is the tendency of objects to resist a change of motion, an example is when textbooks are on a desk, they stay stationary until picked up.
Describe friction as a contact force
Friction is the force created when things rub together, friction is a contact force as it needs two objects to rub together to work.
Describe examples of ways to increase and decrease friction
Friction can be increased by rubbing harder or on rougher surfaces, this is as in rough surfaces there will be more interlocking creating greater frictional force.
You can decrease friction by adding oil or lubricants to the surfaces, this helps to make the surfaces more slippery and harder to apply frictional force to,
You can also decrease friction by using smoother surfaces, smooth surfaces have less groves and bumps which makes it generally harder to apply frictional force.
Identify non contact forces acting at a distance but within a field
Gravitational force, magnetic force, electrostatic force
Magnetic field, gravitational field, electrostatic field
Fields are the area where a force affects you up the greatest, for example we are in the Earths gravitational field and we are pulled to the centre of the earth by gravity
Describe gravity as a non contact, attractive force, which exerts a pulling force
Gravity is a non contact force as it works through a field, it attracts us to the Earth’s core, the more weight we have the stronger gravitational pull we have. Gravity pulls us towards the Earth, the further we are out of a gravitational field, the less gravity will be exerted into us.
Define magnetic force as a non contact force
Magnetic force is non contact as you can feel the force between 2 magnets in the same magnetic field, they will either try to attract to each other or try to swerve out of the way
Magnets that face opposite poles will attract but when they are the same they will try to repel.
A magnetic field should be drawn with arrows pointing towards the South Pole and the lines should get further away the weaker the force is, magnetic force lines cannot cross
State the rules for attraction and repulsion of magnetic poles
Like charges repel each other; unlike charges attract. Two negative or positive forces repel while a negative and a positive attract
Describe the structure of an atom, using the terms protons, neutrons and electrons, to explain how objects acquire an electrostatic charge
Electrostatic force is a non contact force, it can push or pull other objects.
An atom is made up of electrons, protons and neutrons, electrons are negatively charged, protons are positively charged, and neutrons are neutrally charged. The more electrons an atom has it means it is negatively charged, the more protons a atom has it means it’s positively
charged. If it has an equal amount, it is neutrally charged, objects acquire charge electrostatic by rubbing objects against each other.
The nuecleus is at the centre of the atom and is made up of protons and neutrons
On the outer shell there are electrons
Using the Law of Electrostatics, describe the behaviour of charged objects depends on its charge.
The behaviour of a charged object (according to Coulomb’s law) is that unlike charges attract and like charges repel, the attraction and repulsion acts along the line between two charges.
What are the three magnetic metals
Cobalt, nickel and iron
How do objects acquire electrostatic charge
By having more electrons then protons
