Answer:
636.4 J
Explanation:
The potential energy between one of the charges at the corner of the square and the fifth identical charge is U = kq²/r where q = charge = +50 × 10⁻⁶ C and r = distance from center of square. = √2 m (since the midpoint of the sides = 1 m, so the distance from the charge at the corner to the center is thus √(1² + 1²) = √2)
Since we have four charges, the additional potential energy to move the charge to the centre of the square is U' = 4U = 4kq²/r
U' = 4kq²/r
= 4 × 9 × 10⁹ Nm²/C² (+50 × 10⁻⁶ C)²/√2 m
= 900 Nm²/√2 m
= 636.4 J
Answer:
80.17 cm
Explanation:
Taking moments of forces about the center, the total clockwise moments is equal to the total counter clockwise moment:
Force * distance (counter clockwise) = force * distance (clockwise)
0.24 * 9.8 * (50 - 6) = 0.35 * 9.8 * (x - 50)
0.24 * 44 = 3.43x - 171.5
103.5 = 3.43x - 171.5
=> 3.43x = 103.5 + 171.5
3.43x = 275
x = 275/3.43 = 80.17 cm
Answer:
1.832 kgm^2
Explanation:
mass of potter's wheel, M = 7 kg
radius of wheel, R = 0.65 m
mass of clay, m = 2.1 kg
distance of clay from centre, r = 0.41 m
Moment of inertia = Moment of inertia of disc + moment f inertia of the clay
I = 1/2 MR^2 + mr^2
I = 0.5 x 7 x 0.65 x 0.65 + 2.1 x 0.41 x 0.41
I = 1.47875 + 0.353
I = 1.832 kgm^2
Thus, the moment of inertia is 1.832 kgm^2.
We are given
r = 0.6 m
n = 1.5
D = 0.6 m, R1 = 30 cm
R2 = 120 cm
We are asked to get the focal length and the distance of the focal plane from the lens
We use the formula
1 / f = ( n - 1) (1/R1 - 1/R2)
Substituting and solving for f
1/ f = (1.5 - 1) (1/30 - 1/120)
f = 80 cm
The focal length is 80 cm and the distance of the focal plane from the lesn is 80 cm - 30 cm = 50 cm.<span />
