A double-convex lens is made of glass with an index of refraction of 1.25. One surface has twice the radius of curvature of the other. The focal length is 60 mm. What are the two radii

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

Yvette hangs a 2.4kg bird feeder in the middle of a rope tied between two trees. the feeder creates a tension of 480 n in each side of the the rope.

If element x has 99 protons how many electrons does it have