1.A bob of mass 140 g is hanging from a string of length 31 cm. What is the period of the pendulum?

2. If you wanted to double period of the pendulum, what should you do?


A) Quadruple the length of the string.


B) Double the length of the string.


C) Halve the length of the string.


D) Double the mass.





3. Consider the equation for the period of a pendulum. In a plot of T2 vs. l you will get a straight line. The slope of the line is given by





A) 2pi/g


B) 4pi2/g


C) 2pig1/2


D) g1/2





4. All clocks used to keep time by the swinging of a pendulum which had a period of 1 second. If one of these clocks were taken to the moon, how would the time kept by the clock change?





A) The moon clock would keep the same time as the earth clock.


B) It would depend on spring constant of the pendulum.


C) The moon clock would run slower than the earth clock.


D) The moon clock would run faster than the earth clock.





5. A mass of 120 g is hanging from a spring and is set into simple harmonic motion. If the period of the pendulum is 1.163 s, what is the spring constant?

1.A bob of mass 140 g is hanging from a string of length 31 cm. What is the period of the pendulum?
1. T= 2pi sqrt (L/g)


= 2 x 3.14 x sqrt (0.31/10) = 1.1 sec





2. from the equation T= 2pi sqrt (L/g),


to double T, you got to quadruple L, therefore answer is (A)





3. from the equation T= 2pi sqrt (L/g),


T^2 = [2pi sqrt (L/g)]^2


= 2pi^2 (L/g)


answer c (the gradient)





4. moon has a smaller g. so, T is bigger, answer is C.





5. T= 2pi sqrt (m/k)


1.163 = 2pi sqrt (0.12/k)


Find k.