A man pushes a lawn mower on a level lawn with a force of 193 N. If 39% of this force is directed downward, how much power does he expend in pushing the mower 4.9 m in 12 s?
Fn = 193 - 0.39*193 = 117.73 = Net force.
Power = Fn * d/t
Power = 117.73 * 4.9/12 = 48.1 J/s =
48.1 Watts.
Well, let's break this down. If 39% of the force is directed downward, then the remaining 61% of the force is directed forward. So, we can calculate the forward force by multiplying the total force (193 N) by 61%:
Forward force = 193 N * 61% = 117.73 N
Now, let's calculate the work done by multiplying the forward force by the distance traveled:
Work = Forward force * Distance = 117.73 N * 4.9 m = 576.677 N·m
Finally, we can calculate the power expended by dividing the work done by the time taken:
Power = Work / Time = 576.677 N·m / 12 s = 48.056 W
So, the man expends approximately 48.056 watts of power in pushing the lawn mower. And I must say, he's positively energized!
To calculate the power expended, we need to use the formula:
Power = (Force x Distance) / Time
First, let's calculate the net force exerted by the man:
Net Force = Force - Force directed downward
Given that 39% of the force is directed downward, the force directed downward can be calculated as:
Force directed downward = 0.39 x Force
Substituting the values:
Force directed downward = 0.39 x 193 N = 75.27 N
Therefore, the net force is:
Net Force = Force - Force directed downward
Net Force = 193 N - 75.27 N
Net Force = 117.73 N
Now, let's calculate the power expended:
Power = (Force x Distance) / Time
Power = (117.73 N x 4.9 m) / 12 s
Power = 574.77 N.m / 12 s
Hence, the man expends approximately 47.89 Watts of power in pushing the mower.
To calculate the power expended by the man to push the lawn mower, we need to use the formula:
Power = Force × Distance ÷ Time
First, let's calculate the net force applied by the man. Since 39% of the force is directed downward, we can find the downward force using the equation:
Downward Force = 0.39 × Total Force
Downward Force = 0.39 × 193 N = 75.27 N
To calculate the net force, we need to subtract the downward force from the total force:
Net Force = Total Force - Downward Force
Net Force = 193 N - 75.27 N = 117.73 N
Now we can substitute the values into the power formula:
Power = Net Force × Distance ÷ Time
Power = 117.73 N × 4.9 m ÷ 12 s
Power = 477.37 J ÷ 12 s
Power = 39.78 Watts
Therefore, the man expends approximately 39.78 watts of power to push the lawn mower.