Force & Pressure Notes

• An object immersed in a liquid experiences an upward force exerted by the liquid.
• This force decides whether the object will float or sink. If the upward force exceeds the weight of the object, the object floats; if the weight of the object exceeds the upward force, the object sinks.
• The instrument used to measure pressure is pressure gauge or open manometer tube.

Variation of Liquid pressure with depth:

• Area of knife blade is extremely small to create high pressure for easy cutting.
• Syringes used to take blood for blood tests work due to the pressure of the liquid.
• Skis have large area to reduce the pressure on the snow
• Pressure under the studs on the soles of football shoes is high enough for them to sink into the ground for extra grip.