Arock dropped from a high platform is moving at 24 ms downward when it strikes the ground. ignore air resistance. how fast was the rock moving when it had fallen only one-fourth of the distance to the ground?

The slope of a velocity time graph over any interval of time gives the during that interval

Certain bacteria (such as aquaspirillum magnetotacticum) tend to swim toward the earth’s geographic north pole because they contain tiny particles, called magnetosomes, that are sensitive to a magnetic field. if a transmission line carrying 100 a is laid underwater, at what range of distances would the magnetic field from this line be great enough to interfere with the migration of these bacteria? (assume that a field less than 5% of the earth’s field would have little effect on the bacteria. take the earth’s field to be 5.0 * 10-5 t, and ignore the effects of the seawater.)

Apoint charge +q is at the origin. a spherical gaussian surface centered at the origin encloses +q. so does a cubical surface centered at the origin and with edges parallel to the axes. select "true" or "false" for each statement below. the electric flux through the spherical surface is greater than that through the cubical surface. suppose (for this statement only), that q is moved from the origin but is still within both the surfaces. the flux through both surfaces remains unchanged. the area vector and the e-field vector point in the same direction for all points on the spherical surface. the e-field at all points on the spherical surface is equal due to spherical symmetry. the flux through the spherical gaussian surface is independent of its radius.