Is a measure of the distance an object travels in a certain amount of time.

How would doubling the made of an object change the objects potential energy

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

Idon’t quite understand this problem