Forces Flashcards
Ways that forces affect an object
- change its shape
- change its size
- change its velocity
- change its direction of motion.
Forces unit
Newton (N)
Are forces vectors or scalars
Vector
Unbalanced forces = ?
Resultant force and change in speed
Balanced forces = ?
No reesultant force, so object is stationary or moving at a constant speed
equation for:
Forces
F = ma
Force = mass * acceleration
For an object moving in a circular path
More forces is needed if
When these increase:
* mass
* speed
* radius
Equation for: (and unit)
Spring constant
k = F/x N/cm
Spring constant = Force / extension
Define:
Spring constant
The force needed to stretch a spring or wire by one unit of length. Measured in N/m.
If a spring requires a larger force to stretch then …
It has a higher spring constant
Define:
Limit of proportionality
The highest force that can be applied before the extension of a spring or wire is no longer proportional to the force applied. Deformation occurs above this point.
Hookes law doesnt apply after this point
Define:
Moment
A turning force
Equation for: (Add unit)
moment
moment = force * perpindicular distance to the pivot
Nm
What is:
The principle of moments
A system will not rotate (it will balance) if the clockwise and anti-clockwise moments are equal.
total clockwise moment = total anticlockwise moment
In order to hold a light wheelbarrow at a steady height, a vertical force of 200 N is required on the handle. The length of the wheelbarrow is 1.6 m. The horizontal distance from the handle to the wheel is 1.2 m, and the horizontal distance from the wheel to the load is 0.7 m. Calculate the mass of the load.
340 N so 34.7kg
Define:
Centre of gravity
The imaginery point within an object that the mass and weight of the object is evenly dispersed around (also known as the centre of mass).
Average position of all the mass in that object
If the centre of gravity is low, then the object is ___
more /less stable
More
and vice versa
in terms of centre of gravity
Factors that lead to more stability
Bigger base
Lower centre of gravity
if forces are unbalanced _______
the object accelerates
Define:
friction
the force between two surfaces that oppose the motion and produces heating.
Define:
Air resistance
the frictional force acting on an object moving or falling through the air.
Define:
Drag
the frictional force acting on an object moving through a liquid.
in a length-force applied graph (springs)
What does thet gradient represent
The spring constant and it should be directly proportional
When will a beam be balanced
If clock and anti clockwise forces are equal
Equation:
Force
spring constant in the equation
F = kx
If an object is moving in a circle
There is a force acting perpinduclar to direction of movement and towards the center of the circle.
