A box moving to the right experiences four forces, as shown. Key
F = 10 N
F = Normal Force
F, = Friction Force
F Force due to Gravity
FA = Applied Force
F, = 15 N
F = 15 N
F = 10 N
If these forces are applied for a given time interval, t, which statement describes what the box will do during
that time?
A. The box will slow down during the time interval.
B. The box will maintain a constant velocity.
C. The box will speed up during the time interval.
D. The box will change direction but not speed.

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.)