please answer these question.
The thunder is heard during a thunderstorm three seconds after the flash of lightning. If the speed of sound is 342 m/s,find the distance of which lightning took place.
The speed of sound in water is 1500 m/s. A boat man hears an echo 3 s after sending a sound pulse into the sea. What is the depth of the sea?
An observer stands at a distance of 660 m from a cliff and fires a gun. After what time period will he hear the echo , if the sound travels at a speed of 330 m/s?
The sound of thunder is heard 3 s after the flash of lightning. if the speed of sound is 340 m/s. Find the height of the cloud.
The speed of sound in water is 1600 m/s. A boat man hears an echo 3 s after sending an ultrasonic sound into the sea. What is the depth of the sea?
If the time taken by a wave to pass through a point is 0.002 s. What is its frequency?
Answers
Here's a simple method for calculating your distance from a lightning strike.
Just count the number of seconds that pass between a flash of lightning and the crack of thunder that follows it, then divide that number by five. The resulting number will tell you how many miles away you are from where lightning just struck.
Five seconds, for example, indicates the lightning struck 1 mile away, and a 10-second gap means the lightning was 2 miles away.
This technique is called the "flash-to-bang" method, and it can keep you safe during rainy summer weather. The National Weather Service recommends taking cover if the time between the lightning flash and the rumble of thunder is 30 seconds or less, which indicates the lightning is about 6 miles away or closer.
This method is based on the fact that light travels much faster than sound through the atmosphere: Light travels at 186,291 miles per second (299,800 km/s), whereas the speed of sound is only about 1,088 feet per second (332 meters per second), depending on air temperature.
For metric-system conversions, follow this method: Sound travels at about 340 m/s, so multiply the number of seconds you counted by 340, and you'll know how many meters away lightning struck. A three-second count, then, would place the lightning strike about 1,020 m away, or roughly 1 km.