After a group of gang members learned that their friend had died in a seemingly random accident, several of the friends started blaming a rival gang for the death. Even though there was no evidence whatsoever that the death had been intentional, the more the friends talked, the more passionate they became in their belief that an act of revenge was necessary. What concept from social psychology may contribute to an act of violent revenge in this case

Groupthink

Explanation:

Based on the scenario being described within the question it can be said that the social psychology concept that would contribute to this is known as Groupthink. This describes that phenomenon in which the desire for a group of individuals to get along leads to that group making irrational or dysfunctional decisions. Such as an violent act of revenge.

uses : -

1.aneroid barometers primarily measure whether pressure is rising or falling.

2.aneroid barometers are often used for reading pressure in homes and recreational boats.  

3.other uses may include barographs in meteorology and altimeters in modern aircraft.  

4.this type of barometer can announce whether a high or low pressure system is coming or whether it is becoming more intense.  

5.there are different types of aneroid barometers, such as the altimeter, which measures altitude, or distance above sea level.  

6.another example is a barograph, which is a modified aneroid barometer that provides constant readings of atmospheric pressure on graph paper.  

7.when used in this capacity, the aneroid barometer can store a week's worth of data.

android diameter a device for measuring atmospheric pressure , often specially calibrated for use as an altimeter ,consisting of a box or chamber partially exhaused of air, having an elastic top and a pointer to indicate the degree of compression of the top caused by the external air

refer to the attachment for the characteristics : -

answer; code of federal regulations;