Answer:
U_f = (U_o)/2)
Explanation:
The capacitance of a given capacitor is given by the formula;
C = ε_o•A/d
While energy stored in plates capacitor is given as; U_o = Q²/2C
Now,we are told that that all the dimensions of the capacitor plate is doubled. Thus, we now have;
C' = ε_o•4A/2d
Hence, C' = 2C
so capacitance is now doubled
Thus, the final energy stored between the plates of capacitor is given as;
U_f = Q²/2C'
From earlier, we saw that C' = 2C.
Thus;
U_f = Q²/2(2C)
U_f = Q²/4C
Rearranging, we have;
U_f = (1/2)(Q²/2C)
From earlier, U_o = Q²/2C
Hence,
U_f = (1/2)(U_o)
Or
U_f = (U_o/2)
Answer:
2 m/s^2
Explanation:
from the question
v=15 m/s
t=7.5
a=?
from the first equation of motion
v=u+at
where,
v=final velocity
u=initial velocity
a=acceleration
t=time
from the question (u) will be zero because the body started at rest
v=u+at
15=(0)+a×7.5
15=7.5a
a=15/7.5
a=2 m/s^2
