Asimple pendulum is mounted in an elevator. what happens to the period of the pendulum (does it increase, decrease, or remain the same) if the elevator

(a) accelerates upward at 5.0 m/s2;
(b) moves upward at a steady 5.0 m/s ;
(c) accelerates downward at 5.0 m/s2;
(d) accelerates downward at 9.8 m/s2

Explanation:

Time period of Simple pendulum is given by

where L=length of Pendulum

g=acceleration due to gravity

(a)When elevator is accelerating upward with

effective g will be g+a=9.8+5

therefore time period will decrease

(b)When elevator is moving upward with 5 m/s

effective g will be g as there is no added acceleration

therefore time period will remain same

(c)When elevator is accelerating downward with

effective g will be g-a=9.8-5

therefore time period will increase

(d)When elevator is accelerating downward with

effective g will be g-9.8=0

therefore time period will become infinite

the answer is b

explanation:

the order for strong to weak forces such as

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

the fundamental forces are those forces that act between to objects or element to make interactions. there are four types of fundamental forces such as strong and weak nuclear forces (due to protons and electrons), electromagnetic force (due to the motion of electrons) and gravitational force (due to orbital movement of the planet). if these forces are arranged on the basis of their maximum strength then the order is

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force