Apendulum loses 12 seconds at temperature 40 degree celsius and gain 4 sec at 20 degree celsius at what temperature it will show the correct time

25 degrees

Explanation:

The time period of a pendulum is given by,

t=2π  

=> Δt=2/g(Δl/2)

and we also know that,

Δl= αΔT

=> Δt= /(αΔT)

=> Δt₁/Δt₂= ΔT₁/ΔT₂

=> 12/4= (40-T)/(T-20)

=>3T- 60= 40- T

=> T= 25°

answer:

as i it is pin 2 will fall later as the air should reach the pin and pin 1 will fall earlier as the rod gets hotter

the  experiment  intended to measure the speed of earth in ether. later albert einstein in special theory of relativity explained the negative result of  michelson morley experiment. according to special theory of relativity, the light travels at same speed in all inertial frames of reference.