P8: Forces In Balance Flashcards
What is a vector quantity?
A quantity with SIZE and DIRECTION
What is a scalar quantity?
A quantity with SIZE but NO direction
What is distance?
The distance travelled in total
What is displacement?
The distance between where something started moving and where it stopped
What are some examples of vector quantities?
Velocity, force, acceleration, weight, displacement
What are some examples of scalar quantities?
Mass, energy, speed, time, distance, power
What is a force in physics?
A push or a pull that acts on an object, measured in Newtons (N)
If you apply a force to an object, what different things can happen?
It can change shape (squeeze or stretch), can change direction, can change speed
What is the difference between a contact and non-contact force?
A contact force is when there is physical touch in order for the force to happen
What are some examples of contact forces?
Tension
Air resistance
Friction
Thrust
What are some examples of non-contact forces?
Electrostatic
Magnetic
Gravitational
Nuclear
What is newtons third law of motion?
When two objects interact with eachother they exert Equal and Opposite forces on eachother
What is a resultant force?
A single force that describes all of the forces that are operating on an object
What is a balanced force?
When two forces are the same size and in an opposite direction
What is an unbalanced force?
When one of the two forces in opposite directions is larger than the other
What is a moment?
Turning force around a fixed pivot
What is a moment equal too?
Force X distance
What are force multiplyers?
Force multiplyers multiply the applied force, allowing you to lift more for less work
What is the centre of mass?
The point of an object where its mass can be thought of as being the most concentrated
How do you find the centre of mass on a regularly shaped object?
You draw the lines of symetry and where they all cross is the centre of mass
How do you find the centre of mass on an irregular shaped object?
You hang a plumb line from different points on the shape and draw a line where it hangs for each of them, where these lines cross is the centre of mass
If an object is equilibrium what can you say about all the forces?
That they are balanced
If someone is sat 2m from the pivot of the seesaw and is applying a 300N force, what is their total force being applied?
2 x 300 =
600N
How do you figure out the resultant force of a shape without a right angle?
1) Figure out the scale
2) Draw in the 2 lines you have been given at the right angles and to scale
3) Measure out the lenghts and angles of those lines to draw them again to make a pallelogram
4) Draw a line from the starting point to the point opposite from it, and meassure the angle and size of that resultant force
