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• Super Challenge:

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  Challenge:

Key Questions:

1. (Physics only) What states can be fluids?
   • (Physics only) A fluid can be either a liquid or a gas.
2. (Physics only) Pressure in fluid causes a force in what direction to the surface?
   • (Physics only) The pressure in fluids causes a Force normal (at right angles) to any surface.
3. (Physics only) What equation can be used to calculate the pressure of a fluid at the surface?
   • (Physics only) The pressure at the surface of a fluid can be calculated using the equation: pressure = Force normal to a surface area of that surface p = F / A pressure, p, in pascals, Pa Force, F, in newtons, N area, A, in metres squared, m2
4. (Physics only) How can the pressure due to a column of liquid be calculated?
   • (Physics only) The pressure due to a column of liquid can be calculated using the equation: pressure = height of the column ? density of the liquid ? gravitational field strength [ p = h ? g ] pressure, p, in pascals, Pa height of the column, h, in metres, m density, ?, in kilograms per metre cubed, kg/m3 gravitational field strength, g, in Newtons per kilogram, N/kg
5. (Physics only) What two factors increase the pressure at a point in a liquid?
   • (Physics only) In a liquid, pressure at a point increases with the: Height of the column of liquid above that point: Density of the liquid.
6. (Physics only) How does pressure change as you get deeper in the sea?
   • (Physics only) Pressure increases as you get further from the surface of the water due to the Force of the Particles pushing down on the ones below.
7. (Physics only) How do differences in pressure create the force of upthrust?
   • (Physics only) A partially (or totally) submerged object experiences a greater pressure on the bottom surface than on the top surface. This creates a resultant Force upwards. This Force is called the upthrust.
8. (Physics only) What factors influence whether an object floats or sinks?
   • (Physics only) An object will float or sink in a fluid depending on the relative densities of the object and Fluid. If the object is less dense it will float and if it is more dense then it will sink.
9. (Physics only) What is the atmosphere?
   • (Physics only) The atmosphere is a thin layer (relative to the size of the Earth) of air round the Earth.
10. (Physics only) What happens to the density of the atmosphere as the altitude increases?
    • (Physics only) The atmosphere gets less dense with increasing altitude
11. (Physics only) What creates atmospheric pressure?
    • (Physics only) Air molecules colliding with a surface create atmospheric pressure.
12. (Physics only) What happens to the weight of air above a surface as the height of that surface is increased above ground level?
    • (Physics only) The number of air molecules (and so the weight of air) above a surface decreases as the height of the surface above ground level increases.
13. (Physics only) Why does atmospheric pressure decrease with an increase in height?
    • (Physics only) As height increases there is always less air above a surface than there is at a lower height. So atmospheric pressure decreases with an increase in height
14. (Physics only) How would the particles in the air be arranged close to the Earth's surface then getting further up with altitude.
    • (Physics only) The air Particles become more spread out/less dense as the altitude increases, decreasing the atmospheric pressure as there are less frequent collisions with the air Particles.
15. (Physics only) Why does atmospheric pressure vary with height above the surface?
    • (Physics only) The air Particles become more spread out/less dense as the altitude increases, decreasing the atmospheric pressure as there are less frequent collisions with the air Particles.