Question

1. In studies of harmonic systems and of circular motion, radians are always used instead of degrees in derivations. This is ________________.

   		an arbitrary choice or preference.
   		necessary and related to the arc length equation.
   		because there is not a one-to-one mapping of theta to sin(theta) when using degrees.
   		because we like Greece more than Babylon.

4 points   

QUESTION 12

1. Which of the following is not unique to simple harmonic systems and could apply to any harmonic system?

   		Motion is described by sinusoidal functions.
   		The amplitude has no effect on the period of the motion.
   		Subject to a linear restoring force alone.
   		Has a well-defined period of motion.

4 points   

QUESTION 13

1. The mass of a pendulum without friction forces affects its motion.

   		A little bit.
   		Not at all.
   		Dramatically.
   		Only when mass is large compared to string length.

4 points   

QUESTION 14

1. While viewing two phase portraits, one is a perfect circle and the other is an ellipse. There is

   		more energy in the first system.
   		nothing fundamentally different about the two systems.
   		more damping in system one.
   		energy being added to the first system.

4 points   

QUESTION 15

1. Centripetal force is

   		always directed inward toward the path's center.
   		always directed outward opposite the path's center.
   		directed either inward or outward along the radial direction.
   		dependent on the details of any given problem.

Answer 1

The answers are given below.

12. Answer: Subject to a linear restoring force alone

Explanation: Besides linear restoring force other forces also act in simple harmonic motion.

13. Answer: Not at all.

Explanation:The mass of a pendulum without friction forces does not affect its motion.

14. Answer: nothing fundamentally different about the two systems.

Explanation:While viewing two phase portraits, one is a perfect circle and the other is an ellipse. There is nothing fundamentally different about the two systems, because in both system the object is subjected to a central force. The only difference is in the eccentricity of their path.

15. Answer: always directed outward opposite the path's center.

Explanation: Centripetal force is always directed outward opposite the path's center.

Thank You.