The Pitch of a sound depends upon the speed of the vibrations causing it. This is called the frequency. The frequency of a sound is measured in Hertz (Hz) after the German sci â¦ entist Heinrich Rudolf Hertz(1857-1894)  1 Hertz = 1 Vibration Per Second. 3 people found this useful.
Police declared Simpson a fugitive, and hours later, the infamous low-speed chase began. Approximately 6:45 p.m. on June 17, 1994, police saw Simpson on the expressway in a white Ford Bronco driven by his best friend and former teammate, Al Cowlings. Simpson was riding in the back, and he reportedly had a gun. With the cavalcade of police cars in pursuit, TV helicopters swooped in to join the chase.
Rough Riders on the attack, from Edison's Infantry supported by Rough Riders at El Caney, 1899. MPEG Format (8.4 MB) Help With Video Credits. Teddy Roosevelt and the Rough Riders July 1, 1898. Before becoming President of the United States, Theodore Roosevelt was the Assistant Secretary of the Navy. He resigned in 1898 to organize the Rough Riders, the first voluntary cavalry in the Spanish-American War. The U.S. was fighting against Spain over Spain's colonial policies with Cuba. Roosevelt recruited a diverse group of cowboys, miners, law enforcement officials, and Native Americans to join the Rough Riders.