Assertion: Pressure is scalar. Reason: Pressure acts equally in all directions at a point. MCQ with Answer and Explanation

Explanation:
The distance covered in the nth second is Sn = u + a/2 * (2n - 1). For n=2: 12 = u + a/2 * (3) => 2u + 3a = 24. For n=4: 20 = u + a/2 * (7) => 2u + 7a = 40. Subtracting equations: 4a = 16 => a = 4 m/s^2. Substitute 'a' back: 2u + 3(4) = 24 => 2u = 12 => u = 6 m/s.

Explanation:
r_cm = (m1 r1 + m2 r2)/(m1+m2). Closer to heavier mass.

Explanation:
By definition, the electric potential difference between two points in an electric field is the amount of external work required to move a unit positive charge (1 Coulomb) slowly and without acceleration from one point to the other against the electrostatic force. The SI unit of potential difference is the Volt (Joules/Coulomb).