Forces and energy (Year 8) Flashcards
what type of surface has a large amount of friction
rough surface
what type of surface has a small amount of friction
smooth surfaces
what is the unit used to measure force
newton
A box is pulled to the right with 6 N and to the left with 6 N. The resultant force is
zero newtons
The force of friction is ALWAYS in this direction
opposite to the direction of motion
forces are…
Pushes or Pulls
what is a resultant force
the overall value of the forces acting on an object after considering the direction of the forces
what is an unbalanced force
when the forces are NOT EQUAL to each other in a particular direction. Gives a resultant force
what is a balanced force
the force that does NOT change an object’s motion because the forces are equal and opposite so therefore cancel each other out
mass
the measure of the amount of matter in an object
is gravity a non contact force
yes
what is terminal velocity
the fastest speed reached by a skydiver when the weight and drag forces become equal
define upthrust force
force that allows an object to float in a fluid.
Acceleration is equal to
force divides by a mass
define thrust
this is the push of an engine and acts in the forward direction
what is tension
the force inside a stretched rope , string or reaction. it acts in a direction to return the object to its original shape
forces can cause 3 things to happen, What are they ?
- can cause a change in state
- can cause a change in direction
- can cause a change in speed
what device is used to measure a force
newton meter
name the 8 forces that we have learnt
friction
drag or air resistance
tension
weight
thrust
lift
normal contact
upthrust
simplify
weight= mass x gravitational field strength
w = mg
what is measured in meters per second squared. It tells you how quickly the object is changing its speed, while it is …
acceleration
what is deceleration
If it is slowing down, it is losing speed every second. This is called a deceleration (be careful with the spelling).
mass is equal to …
forces divided by acceleration
force is equal to …
mass multiplied by acceleration
what is the value of the gravitational field strength on the earth
10 N/kg
define weight
the measure of the amount of gravity pulling down on an object. It depends on the gravitation field strength
What MUST you include when representing forces on a diagram
arrow, label, value, unit
The forces of weight ALWAYS acts in what direction
Straight down
what is the unit for mas
kg
what are the units for gravitational field strength
N/kg
