A 60kg boy climbs 70 fligts of stairs each 20cm high in one minute how much powers is developed?
power=work/time=60*9.8*70*.2/60 watts
To calculate the power developed by the boy while climbing the stairs, we need two pieces of information: the work done and the time taken.
First, let's calculate the work done by the boy. The work done is equal to the force exerted multiplied by the distance covered. The force exerted can be found using the boy's weight, which is the product of mass and gravity. Thus, the force exerted by the boy is:
Force = mass x gravity
= 60 kg x 9.8 m/s² (acceleration due to gravity)
Next, we need to calculate the distance covered. Each flight of stairs is 20 cm high, which is equivalent to 0.2 meters. The total distance covered by the boy is the product of the height per flight and the total number of flights climbed:
Distance = height per flight x number of flights
= 0.2 m x 70 flights
Now, we can calculate the work done:
Work = force x distance
= mass x gravity x distance
Substituting the values we have:
Work = 60 kg x 9.8 m/s² x (0.2 m x 70)
Now, we need to calculate the time taken. The question states that the boy climbs the stairs in one minute, which is equal to 60 seconds.
Finally, we can calculate the power developed:
Power = Work / Time
= (mass x gravity x distance) / Time
Substituting the values we have:
Power = (60 kg x 9.8 m/s² x (0.2 m x 70)) / 60 seconds
By evaluating this expression, we can find the power developed by the boy while climbing the stairs.