How much work must be done to bring three electrons from a great distance apart to within 9.0 × 10-10 m from one another (at the corners of an equilateral triangle)?

As we know that change in the potential energy of the system must be equal to the work done to bring the system of charges

here we know that

also here we have

now we will have

So here work done to bring three charges at the vertices of a triangle is given as

weather forecasts are done by collecting data about the current state of the atmosphere mainly the temperature, humidity and wind and using meteorology, to determine the atmosphere that evolves over time. the h and l mean the high and low pressure. the red strip is a warm front. the blue strip is a cold front. the blue and red strip is a stationary front. the purple strip is a occluded front.

explanation: