Atmospheric pressure is the force exerted by the weight of the air in the atmosphere. It acts in all directions and varies with altitude, being higher at sea level and lower at higher elevations. 

While there isn't a single formula for atmospheric pressure, it can be measured using a barometer. The standard atmospheric pressure at sea level is approximately 101.3 kPa (kilopascals) or 1 atm (atmosphere). 

Suction Cups: Suction cups stick to surfaces because the atmospheric pressure outside the cup is greater than the pressure inside, pushing the cup against the surface.

Straws: When you suck on a straw, you reduce the air pressure inside the straw. The higher atmospheric pressure outside pushes the liquid up into the straw.

Weather Patterns: Atmospheric pressure influences weather patterns. High-pressure systems are associated with clear, sunny weather, while low-pressure systems often bring clouds and precipitation.

Airplane Wings: The shape of airplane wings creates faster airflow over the top of the wing and slower airflow underneath, resulting in lower pressure above the wing and higher pressure below, generating lift.

Curveballs in Sports: When a ball is thrown with a spin, the air pressure on one side of the ball is reduced, causing the ball to curve in the direction of the lower pressure.

Chimneys: Wind blowing across the top of a chimney reduces the air pressure there, causing the higher pressure inside the house to push air and smoke up the chimney.