Forces, motion and density (10) Flashcards
Which of these would you use to measure area? m, cm2, g or km
cm2. The 2 should be little and above the m. It stands for squared because we would use square pieces of paper to find the area.
What is measured in centimetres cubed? (cm3)
Volume
What is the relationship between distance, speed and time?
Distance= speed x time
Dead Smelly Turtle triangle.
What is the unit of force? What is force measured in?
Newtons
What is used to measure force?
A force meter or newton meter
What effects the weight of an object?
Its mass (amount of stuff in it) and the force of gravity.
If all forces on an object are balanced what do we know about the object?
It is still or moving at a constant speed.
What will unbalanced forces cause an object to do?
Change direction or speed. This might mean start or stop moving.
What does frictional force do to the movement of an object?
Slow it down
What can we do to reduce air resistance/ drag (a frictional force) on an object?
streamline designs
When is friction useful?
When grip is required, e.g. a tyre on the road, on soles of shoes.
Friction can be a problem in engines as it wastes energy and causes things to get hot? How can friction be reduced?
Lubrication / oil
A turning force can result in an object rotating around a point. What name do we give to this point?
Pivot
Give some examples of where levers are used to increase a force or change the direction of a force.
crowbar, pliers, scissors
What is the relationship between force, pressure and area?
Force = pressure x area
Fat pigs arse triangle
What is the unit for pressure?
Newtons per metre squared (N/m2) or Newtons per centimetre squared (N/cm2)
How do snowshoes or skis stop you sinking in the snow?
They spread your mass over a larger area meaning less pressure on the snow. The opposite of this is why ladies in stilettoes sink in the mud.
What is the density of a material?
A measure of how tightly packed the particles are.
What is the relationship between density, mass and volume?
Mass = volume x density
My Dog Vomits triangle
What is the volume of an object?
The amount of space it takes up
What is the unit of density?
Grams per metre cubed (g/m3) or grams per centimetre cubed (g/cm3)
How do you find the mass of an object?
Put it on some scales (balances) or multiply the density by the volume
How do you find the volume of a regular shaped solid, like a cuboid?
Length x width x height
How do you find the volume of an irregular shaped solid?
Using a Eureka /displacement can and a measuring cylinder
