The minimum power required to lift a mass of 50 kg up to a vertical distance of 8 m in 10 s is: (Take g= 10 m/s²)

The correct answer is 400 W.

Key Points

• The power required to lift a mass is calculated using the formula P = (m × g × h) / t, where m is mass, g is gravitational acceleration, h is height, and t is time.
• Given: m = 50 kg, g = 10 m/s², h = 8 m, and t = 10 s.
• Substituting values: P = (50 × 10 × 8) / 10 = 400 W.
• The minimum power required for lifting the mass is thus 400 Watts.
• Option 1 (400 W) is correct as per the calculation.

Additional Information

• Power: Power is the rate at which work is done or energy is transferred. The SI unit of power is the Watt (W).
• Work: Work is done when a force is applied to an object and it moves in the direction of the force. The formula for work is W = F × d, where F is force and d is displacement.
• Gravitational Force: The force exerted by the Earth on objects due to gravity. The acceleration due to gravity (g) is approximately 9.8 m/s², but for simplicity in calculations, it is often taken as 10 m/s².
• Energy: Energy is the capacity to perform work. Lifting an object vertically against gravity requires energy equal to the product of its weight and the height to which it is lifted.
• Efficiency: In practical applications, the power calculated is the theoretical minimum, assuming 100% efficiency. Real systems may require more power due to energy losses.