A wheel rolls purely on ground. If the velocity of a point 'P as shown on periphery of a body has a velocity equal
1 answer:
Answer:
(1) 120°
Explanation:
The wheel is purely rolling, which means it rotates about an axis through the point where it touches the ground (see Figure 11-6).
The net velocity at point P on the periphery, relative to the bottom of the wheel, is:
v = ωr
where r is the distance from the point at the bottom of the wheel to P (see diagram).
To find r, we need to use some geometry. From Inscribed Angle Theorem, we know the inscribed angle is half the arc angle. And from Thales' Theorem, we know an angle inscribed across a diameter is a right angle.
Therefore:
cos (θ/2) = r / (2R)
r = 2R cos (θ/2)
So the net velocity at P is:
v = 2Rω cos (θ/2)
We want this to equal the velocity at the center of the circle, which is Rω.
Rω = 2Rω cos (θ/2)
1 = 2 cos (θ/2)
cos (θ/2) = 1/2
θ/2 = 60°
θ = 120°
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Answer:
11.9 years
Explanation:
We can find the orbital period by using Kepler's third law, which states that the ratio between the square of the orbital period and the cube of the average distance of a planet from the Sun is constant for every planet orbiting aroudn the Sun:
Using the Earth as reference, we can re-write the law as
where
Te = 1 year is the orbital period of the Earth
re = 1 AU is the average distance of the Earth from the Sun
Tj = ? is the orbital period of Jupiter
rj = 5.20 AU is the average distance of Jupiter from the Sun
Substituting the numbers and re-arranging the equation, we find:
The energy of a single photon at the transmitted frequency is
Answer: Option b
<u>Solution:</u>
Energy of photon is given as
Where c is the velocity of Light
h is planck's constant
λ is the wavelength of photon
Energy of photon can be rewritten as
Where f is the frequency of photon
Frequency of photon is obtained by dividing velocity of light by wavelength of photon.