Gravitation
17 . A satellite orbits the moon far from its surface in a circle of radius r . If a second satellite has a
greater speed, yet still needs to maintain a circular orbit around the moon, how should the second
satellite orbit?
(A) with a radius r
(B) with a radius greater than r
(C) with a radius less than r
(D) Only an eccentric elliptical orbit can be maintained with a larger speed.
(E) No orbit at all can be maintained with a larger speed.
Electrostatics
18 . Which of the following statements about electric potential is correct?
(A) A proton experiences a force from a region of low potential to a region of high potential.
(B) The potential of a negatively charged conductor must be negative.
(C) If the electric field is zero at point P , then the electric potential at P must also be zero.
(D) If the electric potential is zero at point P , then the electric field at P must also be zero.
(E) The electric potential with respect to earth ground can be less than zero at all points on an isolated
wire conductor.19 . A uniform electric field points to the right, as shown above. A test charge can be placed at one of
three points as shown in the above diagram. At which point does the test charge experience the
greatest force?
(A) point A
(B) point B
(C) point C
(D) The charge experiences the greatest force at two of these three points.
(E) The charge experiences the same force at all three points.