I have a row telling me the values of Force, F_{i} and I know that the time interval,Δt is 0.00025 seconds. However, I need to add up everything like this: ΣF_{i} Δt. How can I accomplish this in Excel?

Note: I used impulse in the title because a lot of people seem to have the same problem and I didn't know the correct phrasing for the question.

`0.00025`

, row 3 should have each of the cells in row 1 multiplied by their equivilent in row 2, and then sum everything in row 3? – Paul May 11 '14 at 6:11