Forces in Balance Flashcards
Displacement -
Distance without change of direction
Vectors -
A physical quantity that has magnitude and direction
Scalar Quantity-
A physical quantity that has only magnitude and no direction
How to represent a vector quantity?
- represented by an arrow
- direction of arrow shows direction of vector quantity
- length of arrow represents the magnitude of the vector quantity
define the term work done
the amount of energy transferred to an object when it is moved by a force
equation for work done
work done (J) = Force (N) x Distance (m)
examples of vector quantities:
- acceleration
- force
- momentum
- weight
- GPE
examples of scalar quantities:
- speed
- distance
- mass
- time
why does the change of a shape in a object need more than one force to be applied
Their shape can change by:
- Stretching (forces in opposite directions away from the object)
- Bending (forces that distort the object)
-Compressing (forces in opposite directions towards the object)
what does Newtons 3rd law state
when two objects interact with each other, they exert equal and opposite forces on each other
example of compression of on object
placing a mass on top of a spring placed on a flat surface:
The two forces are:
1. The weight of the mass
2. The reaction force from the surface to the spring
- These two forces are towards each other
example of stretching of on object
mass on the bottom of a vertically hanging spring
The two forces are:
1. The weight of the mass
2. The tension in the spring
These two forces are away from each other
example of bending on object
diving board bending when a swimmer stands at the far end
The two forces are:
1. The weight of the swimmer
2. The reaction force from the block to the dividing board
equation that thinks force, extension and spring constanct
Force (N) = Extension (m) x Spring Constant (N/m)
what is the difference between linear and non-linear relationships
Linear : obey Hooke’s Law and form straight lines
Non-linear : do not obey Hooke’s Law and do not form straight lines when graphed.
definition on velocity =
Speed in a particular direction
what is Newtons 1st law
states that if the resultant forces zero an object at rest says stationary and a moving object will keep moving at the same speed in the same direction
what is Newtons 2nd law of motion:
Acceleration of an object is :
- directly proportional to the resultant force on the object
- Inversely proportional to the mass of the object
acceleration of an object increases if the resultant force on it increases, and decreases if the mass of the object increases.
resultant force definition:
the dingle force that has the same effect as all the forces acting on a object
what does ‘inertia’ mean
the tendency for the motion of an object to remain unchanged (Newtons 1st law) - unless acted on by resultant force, object either stays stationary or moves at constant speed
what is inertial mass
a measure of how difficult it is to change the velocity of an object (Newton 2nd law) - larger masses require larger force to change its velocity
what is stopping distance
the minimum distance required to stop a vehicle in a emergency
stopping distance =
thinking distance + breaking distance
what is thinking distance
distance travelled when reacting
