Well, if your question is how light affects plants,
then you would want to design an experiment that plays aruond with the amount of light a plant gets
thus the thing changing (or variable) would be amount of light
        
             
        
        
        
Potential Energy= 24m * 14kg * 9.8N/kg = 3292.8J
        
             
        
        
        
Answer:
The same pendulum could be adjusted to have the same period, in the equator must have a length of 3.949m.
Explanation:
Tnp= 4 sec
gnp= 9.83 m/sec²
Lnp= 3.97m
Tequ= 4 sec
gequ= 9.78 m/sec²
Lequ=?
Lequ= (Lnp* gequ) / gnp
Lequ= 3.949 m