P3 Flashcards
What is the equation that links charge flow (Q), current (I) and time (F)
Q = I * T
What is the equation for volume?
Volume = length x width x height
What is meant by an object freely suspended
the object has returned to its equilibrium position after the turning force is taken away.
What are some examples of scalars?
Speed, temperature, distance, area, entropy and volume
What are examples of vectors?
Velocity, acceleration, displacement, force, momentum and drag
Define resultant force
The result of 2 vector forces acting against eachother
Equation for velocity
Velocity = speed + direction
Equation for clockwise movement
Total clockwise movement = total anticlockwise movement
How can a vector quantity be drawn and what does it show?
● As an arrow
● The length of the arrow represents the
magnitude
● The arrow points in the associated
direction
What is a force?
A push or pull acting on an object due to an 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 examples of non-contact forces.
- Gravitational forces
- Electrostatic forces
- Magnetic forces
Is force a vector or a scalar quantity?
● Vector
● It has both a magnitude and an
associated direction
Give three examples of vector quantities.
- Velocity
- Displacement
- Force
Give three examples of scalar quantities.
● Temperature ● Time
● Mass
● Speed
● Distance ● Energy
What is weight?
The force that acts on an object due to gravity and the object’s mass.
What quantities does weight depend on?
Weight = mass x gravitational field strength
What is the unit used for weight?
The Newton (N).
What is the unit used for gravitational field strength?
N/kg
What is meant by an object’s centre of mass?
The single point where an object’s weight can be considered to act through.
What piece of equipment can be used to measure an objects weight?
A calibrated spring-balance or newton- meter.
What is the name given to the single force that is equivalent to all the other forces acting on a given object?
The resultant force.
If an object moves 3 metres to the left and then 3 metres back to its initial position, what is the object’s total displacement?
● The object has zero displacement
● Displacement is a vector quantity so it also
involves direction
● The object starts and ends at the same point
State the equation linking distance, speed and time. Give appropriate units.
Distance = Speed x Time Distance (m), Speed (m/s), Time (s)
Newton’s 3rd law
When 2 objects interact with eachother they exert equal and opposite forces on eachother
Newton’s 2nd law
In order to make an object move from rest, the forces must be unequal
What is inertia?
The tendency of an object to continue in its state of rest or uniform motion.
What is an 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 Distance Moment (Nm), Force (N), Distance (m)
What distance measurement is used when calculating a moment?
The perpendicular distance from the pivot to the line of action of the force.
If an object is in equilibrium, what can be said about the moments acting on the object?
The clockwise moments are equal to the anticlockwise moments.
What three parts make up a lever system?
- Load 2. Effort 3. Pivot
Give an example of when a lever may be used to multiply a force.
A wrench, which has a long handle so that the force applied by the user is multiplied.
What determines the moment of a gear wheel?
The size of the wheel.
