For a parallel circuit with two resistors, the total resistance is calculated from the expression:
1/R = 1/R1 + 1/R2
We are given the total resistance, R, which is 20 ohms and R2 which is 75 ohms. We calculate R1 as follows:
1/20 = 1/R1 + 1/75
1/R1 = 11/300
R1 = 27.27 ohms
Consider the upward direction of motion as positive and downward direction of motion as negative.
a = acceleration due to gravity in downward direction = - 9.8 
v₀ = initial velocity of rock in upward direction = ?
v = final velocity of rock at the highest point = 0 
t = time to reach the maximum height = 4.2 sec
Using the kinematics equation
v = v₀ + a t
inserting the values
0 = v₀ + (- 9.8) (4.2)
v₀ = 41.2
<em>False</em>
Explanation:
The electrons cloud patterns are extremely complex and is of no importance to the discussion of electric charge in the atom. More important is the fact that electrons are labile; that is, they can be <em>transferred</em> from one atom to the next. It is through electronic transfer that atoms become charged.
Answer:
0.25 m
Explanation:
Refraction occurs when the velocity or wavelength of a wave changes at the interface between two media.
We know that refractive index=
Wavelength in medium A/wavelength in medium B = velocity in medium A/velocity in medium B
Let the wavelength of medium B be a
0.5/a = 0.3/0.15
0.5 × 0.15 = 0.3 × a
a= 0.5 × 0.15/0.3
a= 0.25 m
