Jeff throws a ball straight up. For which situation is the vertical velocity zero? a. on the way up
b. at the top
c. on the way back down
d. none of the above

The force acting on a beam was measured under the same operating conditions and a sample of 5 data points was collected. this process was repeated by 3 observers. the pooled standard deviations of these 3 data sets was 1.21. determine the true mean force using all pooled data (with a 95% probability). the result should look like this: true mean = mean +/- margin of error