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Ede4ka [16]
3 years ago
12

PLEASE HELP! TRUE OR FALSE!

Physics
2 answers:
SpyIntel [72]3 years ago
8 0

Answer:

<h3>About the firs question.</h3>

The first statement is completely true. An image is attached. You can observe than a concave mirror like it's shown, the focal points is on the optic axis, and all rays converge in that point.

<h3>About the second question.</h3>

<em>A dispersive medium refers to mediums where waves of different frequencies travel at different velocities. </em>In addition, the relation between frequency and degree of refraction of the medium is that waves with lower frequency will bend less when passing through the dispersive medium. For example, if we pass a red light through a medium, and then we pass a violet light, we'll see the difference in the angle of refraction, the violet light will bend more than the red one.

Therefore, the answer to the second question is "<em>dispersive media waves of high frequency refract more than waves of low frequency do".</em>

<em />

<h3>About the third question.</h3>

The reason why Roemer's measurement of the speed of light was inaccurate is:<em> "He did not know the accurate diameter of the Earth's orbit".</em>

At that time, during 1668-1674, the diameter of Earth's orbit wasn't accurate, which added error of delay to his Roemer's measurement. However, he was the first scientist in deduct a finite speed of light, before him, it was known that the speed of light was infinite.

<h3>About the fourth question.</h3>

For convex lenses we have the relation between distances and highnesses:

\frac{d_{o} }{d_{i} }=\frac{h_{o}}{h_{i}}

We have:

f=10.0 \ cm

d=5.0 \ cm

h_{o}=3.0 \ cm

So, we can deduct that the object is d_{o}=15.0 \ cm away from the lens. But, we need to calculate the distance of the image d_{i} with this relation:

\frac{1}{f}=\frac{1}{d_{o} } +\frac{1}{d_{i} }

Replacing all values, we have:

\frac{1}{10}=\frac{1}{15}  +\frac{1}{d_{i}}\\\frac{1}{10}-\frac{1}{15} =\frac{1}{d_{i}}\\\frac{1}{d_{i}}=\frac{15-10}{150}=\frac{5}{150}\\d_{i}=\frac{150}{5}=30

Now, we can calculate the highness of the image:

\frac{d_{o} }{d_{i} }=\frac{h_{o}}{h_{i}}\\\frac{15}{30}=\frac{3}{h_{i}}\\h_{i}=\frac{3(30)}{15}=6

Therefore, the image height is 6 centimetres.

Fed [463]3 years ago
4 0
For the first true or false question, it is true.
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3 years ago
A stubborn, 100 kgkg mule sits down and refuses to move. To drag the mule to the barn, the exasperated farmer ties a rope around
jolli1 [7]

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No, the farmer is not able to move the mule.

Explanation:

Mass =100 kg

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Static friction force,f=\mu N

Normal force=N=mg

Static friction force,f=\mu_s mg=0.8\times 100\times 9.8=784 N

Using g=9.8m/s^2

F<f

Static friction force is greater than applied force.

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At its widest point, the diameter of a bottlenose dolphin is 0.50 m. Bottlenose dolphins are particularly sleek, having a drag c
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Answer:

497.00977 N

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Explanation:

\rho = Density of water = 1000 kg/m³

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v = Velocity of dolphin = 7.5 m/s

r = Radius of bottlenose dolphin = 0.5/2 = 0.25 m

A = Area

Drag force

F_d=\frac{1}{2}\rho CAv^2\\\Rightarrow F_d=\frac{1}{2}\times 1000 \times 0.09(\pi 0.25^2)7.5^2\\\Rightarrow F_d=497.00977\ N

The drag force on the dolphin's nose is 497.00977 N

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\mu = Dynamic viscosity = 1.002\times 10^{-3}\ Pas

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Re=\frac{\rho vd}{\mu}\\\Rightarrow Re=\frac{1000\times 7.5\times 0.5}{1.002\times 10^{-3}}\\\Rightarrow Re=3742514.97005

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The centripetal force acting on the space shuttle
tamaranim1 [39]

Answer:

(4) weight

Explanation:

The centripetal force acting on the space shuttle in orbit is given by:

F=m\frac{v^2}{r}

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m is the mass of the shuttle

v is the tangential speed of the shuttle

r is the radius of its circular orbit

When the shuttle orbits the Earth, the centripetal force that keeps the shuttle in circular motion is given by the gravitational attraction between the shuttle and the Earth, which corresponds to the weight of the shuttle, and it is given by:

F=G\frac{Mm}{r^2}

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G is the gravitational constant

M is the Earth's mass

And this force, therefore, corresponds to the centripetal force.

7 0
3 years ago
Read 2 more answers
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