1.1 Basic physics Flashcards
What are the six base quantities and their units?
- mass (kg)
- length (m)
- time (s)
- electric current (A)
- temperature (K)
- amount of substance (mol)
What is the base SI unit of volume?
m^3
What is the base SI unit of density?
kg m-3
What is the base SI unit of velocity?
ms-1
What is the base SI unit of acceleration?
ms-2
What is the base SI unit of force?
kg ms-2
What is a scalar quantity?
quantity that has magnitude only.
What is a vector quantity?
a quantity which has both magnitude and direction.
What are coplanar vectors?
Vectors acting on the same plane as each other
How do we find the resultant force of two forces acting at right angles to each other?
Pythagoras theorem
How do we find the vertical component?
Sinθ
How do we find the horizontal component?
Cosθ
How do we find the homogeneity of an equation?
compare SI units
What is the equation for density?
p = M/V
What is the volume of a sphere?
4/3 π r³
What is the moment of a force about a point?
the force × the perpendicular distance from the point to the line of action of the force.
What conditions must be true for a body top be in equilibrium?
the sum of anticlockwise moment must be equal to the sum of anticlockwise moments
What is the centre of gravity?
the point where all mass of an object is considered to act
What are the conditions that must be true for a body to be in equilibrium?
- no net forces
- no net moment
