Answer:
D.) 1m/s
Explanation:
Assume the initial angle of the swing is 12.8 degree with respect to the vertical. We can calculate the vertical distance from this initial point to the lowest point by first calculate the vertical distance from this point the the pivot point:

where L is the pendulum length
The vertical distance from the lowest point to the pivot point
is the pendulum length 2m
this means the vertical distance from this initial point to the lowest point is simply:

As the pendulum travel (vertically) from the initial point to the bottom point, its potential energy is converted to kinetic energy:


where m is the mass of the pendulum, g = 10 m/s2 is the constant gravitational acceleration, h = 0.05 is the vertical it travels, v is the pendulum velocity at the bottom, which we are trying to solve for.
The m on both sides of the equation cancel out


so D is the correct answer
The height to which the weight-watcher must climb to work off the equivalent 991 (food) Calories is 0.59 Km
<h3>How to determine the energy. </h3>
1 food calorie = 103 calories
Therefore,
991 food calories = 991 × 103
991 food calories = 102073 calories
Multiply by 4.2 to express in joule (J)
991 food calories = 102073 × 4.2
991 food calories = 428706.6 J
<h3>How to determine the height </h3>
- Energy (E) = 428706.6 J
- Mass (m) = 73.9 kg
- Acceleration due to gravity (g) = 9.8 m/s²
E = mgh
Divide both side by mg
h = E / mg
h = 428706.6 / (73.9 × 9.8)
h = 591.95 m
Divide by 1000 to express in km
h = 591.95 / 1000
h = 0.59 Km
Learn more about energy:
brainly.com/question/10703928
An increase in humidity can strengthen the water cycle, because humidity is essentially boosted evaporation. When you have evaporation, that comes automatically with condensation and precipitation, so rain and cloud cover increases.
The nail will have the ability to pull the pile of paperclips in a magnetic field. Meaning the nail will work as if it is a magnet
Yes
Explanation:
From the graph, we can deduce that the wavelength changes with the speed of the wave.
This is a simple linear graph. A linear graph has a steady gradient and it shows two variables that increases proportionately.
Using the graph, we can establish that as the wavelength of the wave increases the time taken for one wave to pass through increases.
The speed of a wave is given as:
V = fλ
f is the frequency of the wave i.e the number of waves that passes through a point per unit of time
λ is the wavelength of the wave
The vertical axis on the graph shows the time for 1 wave trip, this is the wave period, T
f = 
Therefore;
speed of the wave = 
This can be evaluated by solving slope of the graph and finding the inverse.
We can see that as the speed of the wave changes, the wavelength will change.
learn more:
Wavelength brainly.com/question/6352445
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