The Metabolic power,If we assume that lowering his body has no energetic cost is  667 J/min
The Metabolic power, If lowering of his body needs half of the energy is 1000J/min
<u>Explanation:</u>
<u>1.If we assume that lowering his body has no energetic cost:</u>
<u>Metabolic energy in 5 minutes</u>
         = Increase in potential energy for 150 pushups
         = (89 kg) × (25/100 m) × 150
         = 3337.5 J
<u>Metabolic power</u>
         = (3375.5 J) / (5 min)
         = 667 J/min
The Metabolic power,If we assume that lowering his body has no energetic cost is  667 J/min
<u>2.If lowering of his body needs half of the energy what it costs to raise it.</u>
<u>Metabolic power</u>
          = (667 J/min) × [1 + (1/2)]
          = 1000 J/min
The Metabolic power, If lowering of his body needs half of the energy is 1000J/min