Forces Flashcards
(24 cards)
What is a force?
A force can be a push or a pull.
How can forces be measured?
Forces can be measured using a newtonmeter.
In what unit are forces measured?
Forces are measured in newtons (N).
What are contact forces?
Contact forces occur when objects are touching, for example:
* friction
* drag forces (air resistance and water resistance)
* support forces (e.g., reaction forces)
What are non-contact forces?
Non-contact forces work at a distance, for example:
* gravity
* magnetic force
* electrostatic force
What is friction?
Friction is a contact force that occurs when two objects move against each other.
Why does friction happen?
Friction happens because all surfaces have some roughness, even those that look smooth.
How can friction be reduced?
Friction can be reduced by adding lubrication (e.g., oil or grease).
Why is friction useful?
Friction is needed to walk across surfaces and for bike brakes to work.
What is a drag force?
A drag force is produced when a solid moves through a liquid or gas,
What are examples of drag forces?
Water resistance, air resistance and wind resistance
How can drag forces be useful?
Drag forces can slow something down, such as by using parachutes.
What happens when you stand on the floor?
Your weight pushes the particles in the floor together, holding you down
What are balanced forces?
Same size but act in different directions
What happens to balanced forces?
The balanced forces cancel out, and the object is in equilibrium.
What are unbalanced forces?
when the forces are not the same size
What is the effect of unbalanced forces?
The larger the difference between two sides are, the quicker the object will change speed
Define mass.
the amount of ‘stuff’ something is made of, measured in kilograms (kg).
What is the formula for weight?
weight (N) = mass (kg) * gravitational field strength (N/kg)
What is the gravitational field strength on Earth?
The gravitational field strength on Earth is about 10 N/kg.
What is tension?
Tension is the force that is transmitted through a string, cable etc pulling tight forces on both ends
What is the elastic limit?
The elastic limit is the maximum extent to which a material can be stretched without permanent deformation.
What is a field in physics?
a field is a region of space where a physical quantity (like force) can be felt or measured.
What happens to a field as you get further away from a mass, magnet, or charged object?
The field gets weaker.
