12 B Section review

Question 1

Describe the parts of an ideal pendulum.

Answer 1

A mass concentrated in a single point at the end of a pendulum arm.

Question 2

What was the first recorded use of the pendulum for a non occult purpose? Who was the first European scientist who studied the pendulum?

Answer 2

Dowsing. Christiaan Huygens.

Question 3

What were three historical views of the pendulum? Why is the current paradigm the most useful?

Answer 3

1. Philosophers assumed the rock in a pendulum was trying to move toward the center of the earth according to its “nature”
2. Galileo was taught to see periodic motion of pendulum as the result of an “impetus” that set an object in motion
3. Pendulum was seen to respond to gravitational force & to gain speed in each half swing.
   * Most useful because it helped make revolutionary changes in the way new observations were interpreted.

Question 4

What factors affect the period of a pendulum? What property of a pendulum does not affect its period?

Answer 4

Length of pendulum arm and gravitational acceleration. The mass does not affect its period.

Question 5

How does a pendulum’s period vary with the length of its arm? with its mass? with gravitational acceleration?

Answer 5

Longer arm, longer period, shorter arm, shorter period. Mass = no affect. Gravitational acceleration is assumed to be constant so no affect.

Question 6

T or F: A pendulum works in the International Space Station just as it would on Earth.

Answer 6

False

Question 7

The gravitational acceleration on the surface of Mars is 3.7m/s2. What period would a 0.64 m long pendulum have on Mars?

Answer 7

T = 2pi (sqr root of .64m/(3.7m/ss) ss = s squared
6.28 * (sqr root of .1729 s*s)
T= 6.28 (.4159s) = 2.6118 seconds