Building A and B are 99m apart. A student stands at P, so that his distance from building A is 33m. After clapping his hands once, he hears several echoes. The speed of sound in air is 330m/s
Calculate the time interval between clapping his hands and hearing.
1) the first echo = ?
2) the third echo =?​

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double the distance = divide strength by 4

igneous rocks also form where plates converge. the subducting plate melts as it sinks into the crust of the earth, and the melt rises into the overriding plate forming volcanoes. metamorphic rocks are formed mainly in the lithosphere, wherever there is high pressure and high temperature. -woods

where is the