To solve the problem it is necessary to take into account the concepts of kinematic equations of motion and the work done by a body.
In the case of work, we know that it is defined by,
Where,
F= Force
d = Distance
The distance in this case is a composition between number of steps and the height. Then,
, for h as the height of each step and N number of steps.
On the other hand we have the speed changes, depending on the displacement and acceleration (omitting time)
Where,
Final velocity
Initial Velocity
a = Acceleration
Displacement
PART A) For the particular case of work we know then that,
Therefore the Work to do that activity is 4.41kJ
PART B) To find the acceleration (from which we can later find the time) we start from the previously given equation,
Here,
3 steps in one second
Replacing,
Re-arrange for a,
At this point we can calculate the time, which is,
With time and work we can finally calculate the power
P = \frac{W}{t} = \frac{4.41}{20}
P = 0.2205kW
Answer:
If F is a constant, we can take f = 1
f = m×a
ma = 1
therefore we can say that force is hence proportinal to the product of mass and acceleration.
Answer: 14.5 N
Explanation: NEED SCRATCH PAPER: A flower pot weighing 42.0 N (newtons) is hung above a window by three ropes, each making an angle of 15.0 degrees with the vertical. What is the tension in each rope supporting the flower pot?
✓ 14.5 N
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Everyone knows that one of their favorite past times is sitting in front of the television and watching movies, shows, or playing video games. However with this almost motionless, lazy activity comes a great deal of static physics and mechanics.
When you are sitting down enjoying whatever show it is you may be watching, you actually have several forces acting on you concurrently. For example, by sitting on the couch with no extra weight on you, your weight is equivalent to the normal force, or the force of the couch on you. In addition to the force of the couch of you, if you are leaning on an arm or laying down, a similar force acts on you, except at an angle or incline. The general rule for laying on the couch watching television is that whatever force you exert on an object, that object exerts the same force in the opposite direction, or 180 degrees around.
Answer:
The average power the woman exerts is 0.5 kW
Explanation:
We note that power, P = The rate at which work is done = Work/Time
Work = Energy
The total work done is the potential energy gained which is the energy due to vertical displacement
Given that the vertical displacement = 5.0 m, we have
Total work done = Potential energy gained = Mass, m × Acceleration due to gravity, g × Vertical height, h
m = 51 kg
g = Constant = 9.81 m/s²
h = 5.0 m
Also, time, t = 5.0 s
Total work done = 51 kg × 9.81 m/s²× 5 m = 2501.55 kg·m²/s² = 2501.55 J
P = 2501.55 J/(5 s) = 500.31 J/s = 500.31 W ≈ 500 W = 0.5 kW.
