Ramesh lifts 75 kg of water by 2 m in 5 s. How much power is required for this task? Class 9
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Ramesh lifts 75 kg of water by 2 m in 5 s. How much power is required for this task? Class 9
Question 1.
Ramesh lifts 75 kg of water by 2 m in 5 s. How much power is required for this task? Class 9
Answer:
P = [latex]\frac{W}{t}[/latex] Work done is W = mgh = 75 × 10 × 2 = 1500 J
Power is P = 1500/5 = 300 W v
Question 2.
Car of mass 1000 kg starts from rest and reaches a speed of 20 m/s in 10 s. How much power is required for this task? Class 9
Answer:
Work done on an object = change in its energy
Initial kinetic energy = 0
Final kinetic energy = 1/2 mv² = 14 × 1000 × (20)²
Work done = Change in kinetic energy = 1/2 × 1000 × (20)² - 0 = 200000 J
P = [latex]\frac{W}{t}[/latex] = 200000/10 = 20000 W