IB HL Physics Field strength and potential

A tutorial sheet on the HL concepts of field strength and potential is given below.

1. Define the term electric potential.
2. Define the term electric field strength.
3. Is electric field strength equal to minus the change in potential divided by the change in displacement?
4. What is the relationship between electric field (E) and electric potential (V)?
5. True or false. If the electric potential at a point is zero then the electric field strength at this point must be zero.
6. True or false. If the electric field strength at a point is zero then the electric potential at this point must be zero.
7. True or false. The electric potential at the midpoint of the line joining charges +Q and +Q is a local minimum.
8. True or false. The electric potential at the midpoint of the line joining charges +Q and -Q is a global maximum.
9. Point charges +Q are placed at the vertices of an equilateral triangle of side L. Find the electric potential and field strength at the centre of the triangle.
10. Four point charges +Q are placed at the corners of a square of side L. A point charge -q is placed at the centre of the square. Describe the movement of the charge -q if it (a) pushed a small amount towards a corner charge, and b) pushed a small amount towards the midpoint of a side of the square.

IB Physics Resultant force

A tutorial sheet on resultant force is given below.

1. Define the word force.
2. Define resultant force.
3. A mass on the end of a rod moves in uniform circular motion in a vertical circle. Which of the following are constant in magnitude? (a) the velocity of the mass (b) the acceleration of the mass (c) the force exerted by the rod on the mass (d) the resultant force acting on the mass.
4. A mass is placed at rest on a vertical spring that has its upper end fixed. The mass is pulled down and released from rest. Draw a free-body diagram showing the forces acting on the mass when (a) it is held at rest and (b) after it is released from rest.
5. A smooth rod of length 2L rotates about a vertical axis through its centre in a horizontal plane at a constant angular speed. A particle can slide along the rod. Describe the subsequent movement of the particle if it is released from rest (relative to the rod) at (a) the centre of the rod (b) a distance L/2 from the centre of the rod.
6. In question 5 (b) what is the force that makes the particle slide along the rod? Is this force constant in magnitude?