Using the principle of floatation.
u = w............(a)
Upthrust of fluid is equal to the weight of the object.
Let the volume of the wood be V.
The upthrust u, is related to the volume submerged in water, and that is 1/5 of it volume, that is (1/5)V = 0.2V
Formula for upthrust, u = vdg
where v = volume of fluid displaced
d = density of fluid
g = acceleration due to gravity
weight, w = mg
where m = mass
g = acceleration due to gravity
From (a)
u = w
vdg = mg Cancel out g
vd = m
The v is equal to 0.2V, which is the submerged volume. Notice that the small letter v is volume of fluid displaced, and capital V is the volume of the solid.
d is density of fluid which is water in this case, 1000 kg/m³
0.2V * 1000 = m
200V = m
Hence the mass of the object is 200V kg.
But Density of solid = Mass of solid / Volume of solid
= 200V / V
= 200 kg/m³
Density of solid = 200 kg/m³
Answer:
A theory changes based on new observations and testing.
Explanation:
A scientific theory is a product of multiple trials and repeated experiments. It usually follows after carefully conducting and testing the validity of the hypothesis.
A scientific theory provides an explanation into how something behaves.
A law just states a finding will not explain it.
Most theories are tenable and can be improved upon when new observations and testing are carried out.
This question involves the concepts of the law of conservation of energy and kinetic energy.
The girl's fastest speed is "3.7 m/s".
According to the law of conservation of energy, the girl will have the fastest speed at mean position, which will be calculated as follows:
Loss in Potential Energy = Gain in Kinetic Energy
where,
v = maximum speed = ?
g = acceleration due to gravity = 9.81 m/s²
Δh = change in height = 1.3 m - 0.6 m = 0.7 m
Therefore,
<u>v = 3.7 m/s</u>
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Learn more about the Law of Conservation of Energy here:
brainly.com/question/381281?referrer=searchResults
Answer:
Explanation:
The frequency is 16.0 Hz. That means that 16 of these waves can pass a single point in 1 second. We are given frequency and wavelength. The equation that relates them is
where f is frequency, v is velocity, and λ is wavelength. Putting all this together:
and solving for velocity,
v = 16.0(97.5) so
v = 1560 m/s. This wave can travel 1560 meters in a single second!!! Now that we know this velocity, we can use it in a proportion to find our unknown, which is how long, t, it will take to hear this sound 11000m away. (11 km is 11000m):
and cross multiply to get
1560t = 11000 so
t = 7.1 seconds
