One of the hazards facing humans in space is space radiation: high energy charged particles emitted by the sun. During a solar flare the intensity of this radiation can reach lethal levels. One proposed method of protection for astronauts on the surface of the moon or Mars is an array of large electrically charged spheres placed high above areas where people live and work. The spheres would produce a strong electric field E to deflect the charge particles that make up space radiation. The spheres would be similar in construction to a Mylar balloon, with a thin electrically conducting layer on the outside surface on which a net + or-charge would be placed. A typical sphere might be 5m in diameter. Required:
To repel electrons in the radiation from a solar flare each sphere must produce an Electric field 1 x 10^6 N/C at 25 m from the center of the sphere. What net charge on sphere is needed?

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.

You and a friend (alex) are at a a tree-top adventure park .. . part of the course requires you to climb up a rope. you both climb the same rope in the same amount of time. however, the tension in the rope is greater when alex climbs. who did the most work? alex did - more tension means more force - more force means more work was done you did - less tension means less force - less force means more work was done to find the work done, the force exerted and distance moved are multiplied. a couch is moved twice before you are happy with its placement. the same force was used to move the couch both times. if more work is done the first time it is moved, what do you know about the distance it was moved? when more work was done, the couch was moved less. when more work was done, the couch was moved further. when more work was done, the couch wasn't moved at all. when more work was done, the couch was moved the same distance.

What are similarities and differences between refraction, reflection, diffraction and absorption?