Donna is attempting to make an electromagnet to pick up old nails in and around her driveway. Which of these materials would best for to use for the core to make the strongest electromagnet to pick up the most nails? ​

Why there is no inductive reactance in dc circuits

Determine the amount of work done when a crane lifts a 100-n block form 2m above the ground to 6m above the ground

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.