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) Spherically symmetric about a point in the constellation Sagittarius and concentrated in that direction
Explanation:
The globular clusters are present mainly in the direction of Sagittarius with the center of the system of globular cluster being measured as a spherical cluster cloud such that the center of the Milky Way can be taken as being in the Sagittarius constellation
Answer:
C. Horizontal component of velocity
Explanation:
Object in motion stays in motion,
nothing works against its motion in the horizontal direction, unlike in the vertical direction, gravity pulls object down.
Answer:
78.4 m
Explanation:
To obtain the height of the cliff;
We can use the Relation to obtain the final velocity, v
v = u + at
a = acceleration due to gravity = 9.8m/s²
v = 0 + (9.8*4)
v = 0 + 39.2
v = 39.2 m/s
To obtain the Height, S
v² = u² + 2aS
39.2^2 = 0 + 2(9.8)S
39.2^2 = 0 + 19.6S
1536.64 = 19.6S
S = 1536.64 / 19.6
S = 78.4 m
By using the combined gas law which says that P1V1/T1 = P2V2/T2, assuming constant pressure, the volume at the required temperature can be obtained.((0.002 m3)(50+273.15))/(20+273.15) = volume 2 at 50 degrees C.
This gives the answer 0.0022048 m3
