4. why is it better to use data from three or more seismic stations to find the epicenter of an earthquake?

Data collected from one seismic station can only determine the distance from the epicentre to this station, thus producing a circle with a radius of that distance. If we have two stations, there will be two circles, and these two circles will have two intercepting points (can't determine the exact location). Therefore we need to add another circle, hence another station to know the exact location of the epicentre.

Explanation:

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27

i think the answer would be reserve.