Question

The effective length of a simple pendulum is the sum of the following three: length of string, radius of bob, and length of hook.
In a simple pendulum experiment, the length of the string, as measured by a meter scale, is $92.0$cm. The radius of the bob combined with the length of the hook, as measured by a vernier callipers, is $2.15$cm. The effective length of the pendulum is

• A. $94.1$cm
• B. $94.2$cm
• C. $94.15$cm
• D. $94$cm

Answer 1

The correct option is B $94.2$cm

Length of the string$=92.0㎝$

Radius of bob+length of hook$=2.15㎝$

Total length$=(92.0+2.15)㎝$

$=94.15㎝$

Rounding off to first decimal place$=94.2㎝$

Hence, effective length$=94.2㎝$