If the kinetic energy of a moving body is 450 J and its velocity is 15 m/s, what will be the mass of the body?

Correct option is A

The correct answer is (A) 4 kg

Explanation:
• Kinetic Energy (KE) is the energy an object possesses due to its motion. The mathematical formula linking kinetic energy, mass (m), and velocity (v) is: KE = ½ × m × v².
• We are given KE = 450 J and v = 15 m/s. We need to find the mass (m).
• Plugging the values into the formula:
450 = ½ × m × (15)²
450 = ½ × m × 225
450 = 112.5 × m
m = 450 / 112.5
m = 4 kg.
• Therefore, the mass of the moving body is exactly 4 kilograms.

Information Booster:
• Work-Energy Theorem: The work done by the net force on an object is equal to the change in its kinetic energy.
• Quadratic Relationship: Kinetic energy is directly proportional to the square of the velocity. This means if you double a car's speed, its kinetic energy (and breaking distance) increases by a factor of four.

Additional Knowledge:
• Options B, C, D: These represent mathematical errors. If the mass were 2 kg, the KE would be ½(2)(225) = 225 J. If mass were 5 kg, KE would be 562.5 J. If 3 kg, KE would be 337.5 J.