You are using a co source labeled as having the activity of 3.7 x 1010 counts/second in 1945. what is this source's current activity? (the half-lfe of 0co is 5.271 years.)

Laboratory experiments, observational field studies, and model-building are all examples of different forms of scientific investigations.  in what way do laboratory experiments primarily differ from other forms of scientific investigations?   a.  a laboratory experiment is the only accepted form of investigation within the scientific community.  b.  studies about how things behave in nature or studies involving very large objects are best answered through laboratory experiments.  c.  laboratory experiments involve the identification and control of variables.  d.  data can only be generated through laboratory experiments, not other forms of investigation.

If the new moon happens on january 15th, what shape will it be on february 6th?

Using the free-body diagram, calculate the net force acting on the sled. is the sled in a state of dynamic equilibrium?