force and pressure Flashcards
what is pressure?
the force exerted over an area.
what is the formula for pressure?
pressure pascals = force N ÷ area of surface m²
what is density?
how much mass in contained in a specific volume of a material.
what is the formula for density?
density kg/m³ = mass kg ÷ volume m³
what is the formula for pressure using density?
pressure pascals = depth of liquid m x density of liquid kg/m³ x gravitational field strength N/kg
what is upthrust in a liquid?
in a liquid pressure increases with depth and so the bottom of an object experiences more pressure than the higher parts cause the object to rise.
what is upthrust equal to?
the weight of the fluid that has been displaced. pushed out of the way
when do objects float?
when the weight is equal to the upthrust. the forces are balanced
how does density impact if an object floats?
a very dense object weighs more than the water it displaces meaning it sinks.
what is atmospheric pressure?
the pressure on a surface caused by air molecules.
how does atmospheric pressure change with height? altitude
the pressure decreases.
