Enter the peripheral speed (m/s) and the upstream speed (m/s) into the Calculator. The calculator will evaluate the Apparent Angle. 

Apparent Angle Formula

AA = atan (Vp/V) * 57.2958


  • AA is the Apparent Angle (degrees)
  • Vp is the peripheral speed (m/s)
  • V is the upstream speed (m/s)

To calculate the Apparent Angle, take the arc tangent of the peripheral speed over the upstream speed, then multiply by 57.2958 to convert to degrees.

How to Calculate Apparent Angle?

The following steps outline how to calculate the Apparent Angle.

  1. First, determine the peripheral speed (m/s). 
  2. Next, determine the upstream speed (m/s). 
  3. Next, gather the formula from above = AA = atan (Vp/V) * 57.2958.
  4. Finally, calculate the Apparent Angle.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

peripheral speed (m/s) = 50

upstream speed (m/s) = 30


What is the significance of the Apparent Angle in physical phenomena?

The Apparent Angle is crucial in understanding the interaction between moving objects and the medium they move through, such as in aerodynamics and hydrodynamics. It helps in analyzing how the object’s motion appears to an observer or a device measuring the phenomenon, which is essential for designing efficient systems and devices.

How does the Apparent Angle affect the performance of vehicles?

In vehicles, especially those designed for high speeds like airplanes and boats, the Apparent Angle can significantly affect aerodynamic or hydrodynamic drag and lift. Understanding and optimizing the Apparent Angle can lead to improved performance, fuel efficiency, and stability.

Can the Apparent Angle be applied in fields other than physics?

Yes, the concept of Apparent Angle finds applications in various fields including navigation, where it helps in accurately determining the course of a vehicle relative to the flow of air or water. It’s also used in meteorology for understanding wind directions and in astronomy for measuring the position of celestial bodies.

Why is it necessary to convert the Apparent Angle from radians to degrees?

Converting the Apparent Angle from radians to degrees makes it easier to interpret and apply in practical situations since degrees are a more commonly used unit of measurement for angles in various fields, including engineering, navigation, and even in educational contexts.