Consider a simple pendulum in which a point object of mass 2 kg is suspended fro
ID: 1390783 • Letter: C
Question
Consider a simple pendulum in which a point object of mass 2 kg is suspended from a string. The period of the pendulum is 5 s, and the gravitational acceleration is g = 9.8 m/s2.
What is the length of the pendulum?
(a) 3.1 m
(b) 6.2 m
(c) 9.3 m
(d) 8.3 m
(e) 15.5 m
QUESTION 16*
Suppose the same pendulum (same mass and length) is on a planet such as Jupiter with a gravitational acceleration greater than that of Earth. The period of the pendulum will be
(a) greater than 5 s.
(b) less than 5 s.
(c) equal to 5 s.
QUESTION 17**
Now suppose the pendulum is mounted on the ceiling of an elevator on Earth. In which case is the period of the pendulum larger than 5 s?
(T) The elevator is accelerating upward.
(F) The elevator is accelerating downward.
Explanation / Answer
15) b)6.2 m
We know, T = 2*pi*sqrt(L/g)
==> L = T^2*g/(4*pi^2)
= 5^2*9.8/(4*pi^2)
= 6.2 m
16) (b) less than 5 s.
BeCAUSE t IS INVERSLY PROPORTINAL TO sqrt(g)
17) The elevator is accelerating downward.
if a is the acceleration of the elevator downward
then, T = 2*pi*sqrt(L/(g-a))