Definition of Transverse Waves in Physics
Wave energy, such as sound or pond ripples, moves through substances in one of two different ways: transversely and longitudinally. Transverse waves move up and down or side to side; longitudinal waves move in and out. Transverse waves alternately lift and depress layers of molecules in a substance. Mechanical transverse waves need a medium, such as gas or liquid, through which to travel.
Other People Are Reading
-
Molecular Motion
-
Molecules are constantly moving, even in hard materials, such as steel and diamond. The spaces between the molecules have enough room for them to vibrate. Liquids have slightly more room for molecules to move than solids, and their mutual connections are weak, allowing fluid motion. In gases, molecules are not connected to one another at all, flying in random directions. A transverse wave causes tiny up-and-down movements between the molecules in a substance.
Wave Shape
-
A transverse wave begins from a motionless state. Gradually, it pushes molecules up in a medium, forming a raised ridge, until the wave energy peaks. Molecules then move downward, forming a valley. The molecules move upward again to the original state, and the wave has completed one cycle. You can see this by stretching a Slinky spring across the floor, holding one end steady, and wiggling the other end side to side. A transverse wave travels the length of the spring, reaches the fixed end, and reflects back to the origin.
-
Wave Speed
-
Transverse waves move at speeds determined by the density and hardness of the substance. The frequency and intensity do not affect the speed. In air, the speed varies with altitude and temperature; at 68 degrees Fahrenheit at sea level, it is 344 meters per second. In water, the speed increases to 1,433 meters per second. In iron, waves move at 5,130 meters per second.
Wave Length
-
The length of a transverse wave depends on its frequency and its speed in a material. This is not the distance individual molecules travel; it is the distance between maximum peak points in one full cycle of a wave. To find the wave's length, divide its speed in meters per second by its frequency in cycles per second. In the calculation, the seconds units cancel out, leaving meters. For example, a piano note at 220 cycles per second moving through an iron bar makes a wave 5,130/220 or 23.3 meters long.
-
References
- Photo Credit Jupiterimages/Pixland/Getty Images
