A man whose mass is 75kg walks up a stairs each 20cm high in5seconds.calculate the power expended in watts.[assume g=10m\s2
20cm/step
12 steps?.
d = 20 * 12 = 240cm. = 2.40m.
P = F * d/t = Mg * d/t.
P = 750 * 2.4/5 = 360 J/s = 360 Watts.
It's answer is 352.8 W
Yes 360 is the correct one
To calculate the power expended, we need to use the formula:
Power = Work / Time
First, let's calculate the work done by the man while walking up the stairs.
Work is equal to the force applied multiplied by the distance covered. Here, the force applied is equal to the weight of the person, which is given by the formula:
Force = mass * gravity
Given that the mass of the man is 75 kg and acceleration due to gravity (g) is 10 m/s^2, we can calculate the force:
Force = 75 kg * 10 m/s^2
Next, we need to find the distance covered by the man. The height of each step is given as 20 cm, but we need to convert it to meters:
Distance = number of steps * height of each step
Since the height is given as 20 cm, we convert it to meters by dividing it by 100:
Distance = number of steps * (20 cm / 100)
Now, we need to find the number of steps. Since the stairs are not specified, we'll assume the person walked up a single step:
Distance = 1 * (20 cm / 100)
Finally, we can calculate the work:
Work = Force * Distance
Now, let's substitute the calculated values:
Work = (75 kg * 10 m/s^2) * (1 * (20 cm / 100))
Next, we need to calculate the time. The problem states that the man took 5 seconds to climb the stairs.
Time = 5 seconds
Finally, we can calculate the power:
Power = Work / Time
Let's substitute the values:
Power = calculated work / 5 seconds
By evaluating the equation, we can determine the power expended in watts.
Yeah i think its the right one
You are an Ewuinma
its wrong he take 75kg=750g
ite 75kg=75000g