Answer:
<u>B. the stars of spectral type A and F are considered reasonably to have habitable planets but much less likely to have planets with complex plant - or animal - like life.</u>
Explanation:
The appropriate spectral range for habitable stars is considered to be "late F" or "G", to "mid-K" or even late "A". <em>This corresponds to temperatures of a little more than 7,000 K down to a little less than 4,000 K</em> (6,700 °C to 3,700 °C); the Sun, a G2 star at 5,777 K, is well within these bounds. "Middle-class" stars (late A, late F, G , mid K )of this sort have a number of characteristics considered important to planetary habitability:
• They live at least a few billion years, allowing life a chance to evolve. <em>More luminous main-sequence stars of the "O", "B", and "A" classes usually live less than a billion years and in exceptional cases less than 10 million.</em>
• They emit enough high-frequency ultraviolet radiation to trigger important atmospheric dynamics such as ozone formation, but not so much that ionisation destroys incipient life.
• They emit sufficient radiation at wavelengths conducive to photosynthesis.
• Liquid water may exist on the surface of planets orbiting them at a distance that does not induce tidal locking.
<u><em>Thus , the stars of spectral type A and F are considered reasonably to have habitable planets but much less likely to have planets with complex plant - or animak - like life.</em></u>
Answer:
a) m =1 θ = sin⁻¹ λ / d, m = 2 θ = sin⁻¹ ( λ / 2d)
, c) m = 3
Explanation:
a) In the interference phenomenon the maxima are given by the expression
d sin θ = m λ
the maximum for m = 1 is at the angle
θ = sin⁻¹ λ / d
the second maximum m = 2
θ = sin⁻¹ ( λ / 2d)
the third maximum m = 3
θ = sin⁻¹ ( λ / 3d)
the fourth maximum m = 4
θ = sin⁻¹ ( λ / 4d)
b) If we take into account the effect of diffraction, the intensity of the maximums is modulated by the envelope of the diffraction of each slit.
I = I₀ cos² (Ф) (sin x / x)²
Ф = π d sin θ /λ
x = pi a sin θ /λ
where a is the width of the slits
with the values of part a are introduced in the expression and we can calculate intensity of each maximum
c) The interference phenomenon gives us maximums of equal intensity and is modulated by the diffraction phenomenon that presents a minimum, when the interference reaches this minimum and is no longer present
maximum interference d sin θ = m λ
first diffraction minimum a sin θ = λ
we divide the two expressions
d / a = m
In our case
3a / a = m
m = 3
order three is no longer visible
Answer:
13.1 m/s
Explanation:
Given that a baseball is tossed up into the air at an initial velocity 18 m/s. The height of the baseball at time t in seconds is given by h(t) = 18t−4.9t 2 (in meters).
a) What is the average velocity for [1,1.5]?
To calculate the velocity travelled by the ball, differentiate the function.
dh/dt = 18 - 9.8t
Substitute t for 1 in the above Differential function
dh/dt = 18 - 9.8 (1)
But dh/dt = velocity
V = 18 - 9.8
V = 8.2 m/s
Average velocity = ( U + V ) / 2
Average velocity = (18 + 8.2)/2
Average velocity = 26.2/2
Average velocity = 13.1 m/s
Answer:
Science is changing because little by little scientists descover new things.
Explanation:
Discovery
Hope this helps:)
Answer:
a) 
b) 
c) 
Explanation:
From the question we are told that:
Radius 
Acceleration 
a)
Generally the equation for speed of the car is mathematically given by
b)
Generally the equation for distance traveled of the car is mathematically given by
c)
Generally the equation for time of the car is mathematically given by
