Answer:
407 steps
Explanation:
From the question,
P = mgh/t........... Equation 1
Where P = power, m = mass, g = acceleration due to gravity, h = height, t = time.
Make h the subject of the equation
h = Pt/mg............. Equation 2
Given: P = 746 W, t = 1 minute = 60 seconds, m = 70 kg.
Constant: g = 9.8 m/s²
Substitute into equation 2
h = 746(60)/(70×9.8)
h = 44760/686
h = 65.25 m
h = 6525 cm
number of steps = 6525/16
number of steps = 407 steps
Answer:
t = 6,485 s
, t_step = 25.94 s
the elephant gives 2.3 step very minute
Explanation:
Let's approximate this system to a simple pendulum that has angular velocity
w = √L / g
Angular velocity and period are related
w = 2π / T
T = 2π √g / L
Let's find the period
T = 2π √9.8 / 2.3
T = 12.97 s
Stride time is
t = T / 2
t = 12.97 / 2
t = 6,485 s
Frequency is inversely proportional to period
f = 1 / t
f = 1 / 6,485
f = 0.15 Hz
Since the elephant has 4 legs and each uses a time t, the total time for one step is
t_step = 4 t
t_step = 4 6.485
t_step = 25.94 s
f_step = 1/t_step =0.0385 s-1
Now let's use a proportion rule to find the number of steps in 60 s
#_step = 60 / t_step
#__step = 60 / 25.94
#_step = 2.3 steps
So the elephant gives 2.3 step very minute
Answer: machine's efficiency = 82.2%
Explanation:
Efficiency of a machine is the capability of a machine to convert input to output without waste.
It can be expressed as
Efficiency = output/ input × 100%
Output = 7,023N
Imput = 8,542N
Efficiency = 7,023N/8,542N × 100%
Efficiency = 82.2%
<h2>The hiker will go up to 850 m on the hill</h2>
Explanation:
The total energy gained by the hiker = 140 x 4186 J
This energy is consumed in the potential energy acquired , while climbing up the hill.
The potential energy P.E = mass of hiker x acceleration due to gravity x height
Thus
140 x 4186 = 69 x 10 x h
or h = 
= 850 m
If the 20% of the total energy is used
the height h₀ = 
= 170 m
Answer:
Explanation:
Las condiciones del problema requieren el cálculo de la rapidez inicial de los guijarros. Se sabe que el componente vertical de la rapidez final es cero. Por tanto, el tiempo se determina a continuación: (The conditions of this problems require the calculation of the initial speed of the peebles. It is known that vertical component of the final speed is zero. Therefore, the time is determined herein:).
Además, se determina el componente horizontal de la rapidez inicial (Likewise, the horizontal component of the initial speed is determined):
El guijarro tiene una rapidez de cuando golpea la ventana (The peeble has a speed of when it hits the window).
