Reference frame S' is to pass reference frame S at speed v along the common direction of the x' and x axes, as in Figure. An observer who rides along with frame S' is to count off a certain time interval on his wristwatch. The corresponding time interval Δ t is to be measured by an observer in frame S. Figure gives Δt versus speed parameter B for a range of values for F. The vertical axis scale is set by Δta = 14.0 s. What is interval Δ t if v = 0.98c?