MIXED PRACTICE 13. Until it was recently discontinued, the fastest jet plane in the skies was the Lockheed SR-71 Blackbird. However, this plane did not reach its high speeds through large acceleration. The plane had a mass of 7.7×10^4 kg and was driven by an estimated unbalanced force of about 7.23×10^5 N. What was the acceleration of the Lockheed SR-71?
I am curious about the use of the letter indicator in the sentence ending with 7.23 X10^5 N. Do I use the ELI with the N or not?