Topic 9 🫵🏹 Flashcards
What is a force?
A push or pull acting on an object due to interaction with another object.
What are the two categories that all forces can be split into?
- Contact forces (objects touching)
- Non-contact forces (objects separated)
Give three examples of contact forces.
- Friction
- Air Resistance
- Tension
Give three example of non-contact forces.
- Gravitational forces
- Electrostatic forces
- Magnetic forces
Is force a vector or scalar quantity? Why?
- Vector
- It has magnitude and direction
Give three example of vector quantities.
- Velocity
- Displacement
- Force
Give example of scalar quantities.
- Temperature
- Time
- Mass
- Speed
- Distance
- Energy
How are vectors represented?
- Vector arrows
- Length indicates magnitude
- Arrow indicates direction.
What is the alternative name for the turning effect of a force?
A moment.
State the equation used to calculate the moment of a force. Give appropriate units.
Moment of force = Force x Direction
Moment (Nm), Force (N), Distance (m)
What distance is used when calculating a moment?
The perpendicular distance from the pivot to the line of action of the force.
Turn object is an equilibrium, what can be said about the moments acting on the object?
The clockwise moments are equal to the anticlockwise moments.
How do levers make use of moments?
They increased the perpendicular distance of the force from the pivot, so decrease the force needed to produce the same moment.
How to lubricating levers/gears improve efficiency?
There is less resistance; less energy is wasted/dissipated (as heat) overcoming fictional forces.
