Answer: The plasma membrane is called a selectively permeable membrane as it permits the movement of only certain molecules in and out of the cells. Not all molecules are free to diffuse. If plasma membrane ruptures or breaks down then molecules of some substances will freely move in and out of the cells.
Answer:
1. the electric potential energy of the electron when it is at the midpoint is - 2.9 x
J
2. the electric potential energy of the electron when it is 10.0 cm from the 3.00 nC charge is - 5.04 x
J
Explanation:
given information:
= 3 nC = 3 x
C
= 2 nC = 2 x
C
r = 50 cm = 0.5 m
the electric potential energy of the electron when it is at the midpoint
potential energy of the charge, F
F = k 
where
k = constant (8.99 x
)
electron charge,
= - 1.6 x
C
since it is measured at the midpoint,
r = 
= 0.25 m
thus,
F = 
= k
+ k
=
(
)
= (8.99 x
)( - 1.6 x
)(3 x
+2 x
)/0.25
= - 2.9 x
J
the electric potential energy of the electron when it is 10.0 cm from the 3.00 nC charge
= 10 cm = 0.1 m
= 0.5 - 0.1 = 0.4 m
F = k
+ k
=
(
+
)
= (8.99 x
)( - 1.6 x
)(3 x
/0.1+2 x
/0.4)
= - 5.04 x
J
Answer:
Part a)

Part B)
percentage increase is
%
Explanation:
Part a)
As we know that the beat frequency is

after increasing the tension the beat frequency is decreased and hence the tension in string B will increase
So we have


Part B)
percentage increase in the tension of the string will be given as


now we have

so we have


so we have

percentage increase is
