Forces:
Unbalanced and Balanced Forces:
When same amount of forces act on an object
from different sides, there is an overall balanced
force in the system. Or in other words the forces
are of the same size but act in opposite
directions. When the forces are balanced the
object does not change the direction it is
moving, the object is stationary. When the force
from either side decreases or increases there is
an unbalanced force, and the object starts
moving in the direction of the greater force.
Terminal Velocity of a falling
object:
● When an object falls, there’s initially no
no air resistance or drag its just the
weight of the object falling. The
resultant force of the object is
accelerating downwards.
● As it falls, it accelerates increasing
the speed, now air resistance starts acting on the object
● Eventually there are equal forces acting from opposite directions, the weight, and the drag
force balances out and there is no resultant force.
● When there is no acceleration, and the velocity is constant terminal velocity has reached.
Crumple Zones in cars for safety:
A modern car has crumple zones in the front and the back
which deform/collapse during a collision and increase the
time during which the car is decelerating. In other words,
it absorbs the impact slowly over time. This only work if
the passenger is wearing their seatbelts so the reduced
deceleration applies to their body.
, The turning effect of forces:
● As perpendicular distance from the pivot decreases, we will need more force for a turning
effect on an object. The longer the distance the less force needed.
Electricity:
Safety devices:
Fuses
A fuse is in a shape of a cylinder or cartridge and is placed inside a 3-pin plug. It contains a thin piece
of metal which has a low melting point, this metal piece will melt if there are large amounts of
current, this makes the circuit incomplete. This is a safety device that prevents electrical fires and
shocks to the users. Once the fault causing the increase in current is sorted the fuse is replaced.
● The common fuse sizes used in homes are 3A, 5A and 13A
● They are easy to use and cheap
Earthing:
Unbalanced and Balanced Forces:
When same amount of forces act on an object
from different sides, there is an overall balanced
force in the system. Or in other words the forces
are of the same size but act in opposite
directions. When the forces are balanced the
object does not change the direction it is
moving, the object is stationary. When the force
from either side decreases or increases there is
an unbalanced force, and the object starts
moving in the direction of the greater force.
Terminal Velocity of a falling
object:
● When an object falls, there’s initially no
no air resistance or drag its just the
weight of the object falling. The
resultant force of the object is
accelerating downwards.
● As it falls, it accelerates increasing
the speed, now air resistance starts acting on the object
● Eventually there are equal forces acting from opposite directions, the weight, and the drag
force balances out and there is no resultant force.
● When there is no acceleration, and the velocity is constant terminal velocity has reached.
Crumple Zones in cars for safety:
A modern car has crumple zones in the front and the back
which deform/collapse during a collision and increase the
time during which the car is decelerating. In other words,
it absorbs the impact slowly over time. This only work if
the passenger is wearing their seatbelts so the reduced
deceleration applies to their body.
, The turning effect of forces:
● As perpendicular distance from the pivot decreases, we will need more force for a turning
effect on an object. The longer the distance the less force needed.
Electricity:
Safety devices:
Fuses
A fuse is in a shape of a cylinder or cartridge and is placed inside a 3-pin plug. It contains a thin piece
of metal which has a low melting point, this metal piece will melt if there are large amounts of
current, this makes the circuit incomplete. This is a safety device that prevents electrical fires and
shocks to the users. Once the fault causing the increase in current is sorted the fuse is replaced.
● The common fuse sizes used in homes are 3A, 5A and 13A
● They are easy to use and cheap
Earthing:
