A river of salty water is flowing with a velocity of 2 m s⁻¹. If the density of water is 1.2 g cm⁻³, then the kinetic energy of each cubic metre of water is ______ kJ.
Physics · Mixed Chapter
JEE Main Practice

Question

A river of salty water is flowing with a velocity of 2 m s⁻¹. If the density of water is 1.2 g cm⁻³, then the kinetic energy of each cubic metre of water is ______ kJ.

G1 Physics · Accepted Answer

Step 1: Convert density: ρ = 1.2 g cm⁻³ = 1200 kg m⁻³. Step 2: Mass of 1 m³ of water = ρV = 1200 × 1 = 1200 kg. Step 3: Kinetic energy K = ½mv² = ½ × 1200 × 2² = 2400 J. Step 4: Convert: 2400 J = 2.4 kJ. Final answer: 2.4 kJ.