Static friction is responsible for providing the necessary centripetal force to keep the car moving in a circular path without skidding.

Using the formula: acceleration = (final velocity - initial velocity) / time. Acceleration = (0 - 30) / 5 = -6 m/s².

Deceleration = (final velocity - initial velocity) / time = (0 - 30) / 5 = -6 m/s².

Speed = distance/time = (100000 m)/(7200 s) = 27.78 m/s, approximately 20 m/s.

Total distance = 100 m + 150 m = 250 m. Total time = 10 s. Average speed = total distance / total time = 250 m / 10 s = 25 m/s.

Relative speed = 80 - 60 = 20 km/h. Distance apart after 1 hour = 20 km.

At 90 km/h, the car will travel 180 km in 2 hours.

Time = distance / speed = 150 km / 60 km/h = 2.5 h.

Range of possible speeds = Measured speed ± Error = 60 ± 2 gives 58 to 62 km/h.

F = qE = (3 × 10^-6 C) * (2000 N/C) = 6 × 10^-3 N = 6000 N.

F = q * E = (3 × 10^-6 C) * (1000 N/C) = 3 × 10^-3 N = 3000 N.

Force F = qE = (3 × 10^-6 C) * (2000 N/C) = 6000 N.

F = q * E = (3 × 10^-6 C) * (500 N/C) = 1500 N.

F = q * E = 4 × 10^-6 C * 500 N/C = 2 N.

The total flux through the cube is Q/ε₀. Since the charge is at one corner, the flux through one face is Q/6ε₀.

The total electric flux through the cube is Q/ε₀, but since only 1/6 of the charge is enclosed by the cube, the flux is Q/6ε₀.

By Gauss's law, the electric field inside a uniformly charged spherical shell is zero.

Inside a uniformly charged spherical shell, the electric field is zero due to symmetry.

By symmetry, the flux through one face of the cube is Q/6ε₀, as the charge is shared equally among the six faces.

For r > R, the electric field behaves as if all the charge were concentrated at the center, given by E = Q/(4πε₀r²).

For a point outside the sphere, the electric field behaves as if all the charge were concentrated at the center, hence E = Q/(4πε₀r²).

Inside a uniformly charged spherical shell, the electric field is zero.

As the child moves closer, the moment of inertia decreases, and to conserve angular momentum, angular velocity must increase.

Angular momentum remains constant if no external torque acts, according to the conservation of angular momentum.

As the child moves towards the center, the moment of inertia decreases, thus angular velocity increases to conserve angular momentum.

Total resistance R = R1 + R2 = 3Ω + 9Ω = 12Ω. Using Ohm's law, I = V/R = 12V/12Ω = 1A.

The equivalent resistance for resistors in parallel is 1/R_total = 1/R1 + 1/R2 + 1/R3 = 1/3 + 1/3 + 1/3 = 1Ω. The total current is I = V/R_total = 9V / 1Ω = 9A.

Using Ohm's law, I = V/R = 10V / 5Ω = 2A.

Total resistance R = R1 + R2 = 3Ω + 6Ω = 9Ω. Using Ohm's law, I = V/R = 12V / 9Ω = 1.33A.

The total resistance is 4 + 8 = 12 ohms. The current is I = V/R = 12V / 12 ohms = 1 A. The voltage across the 8 ohm resistor is V = I * R = 1 A * 8 ohms = 8 V.