The magma cools very slowly so that the crystals of different minerals have time to grow. The magma molecules in have time to organize themselves into crystal formations before the magma hardens. The naked eye helps the Intrusive rocks that has large crystals be seen.
Answer:
A total eclipse occurs when the dark silhouette of the Moon completely obscures the intensely bright light of the Sun, allowing the much fainter solar aureole to be visible. During any one eclipse, totality occurs at best only in a narrow track on the surface of Earth. This narrow track is called the path of totality.
A partial lunar eclipse happens when part of the Moon enters Earth's shadow. In a partial eclipse, Earth's shadow appears very dark on the side of the Moon facing Earth.
Answer:
Explanation:
If M be mass of moon and m be mass of spacecraft
potential energy of moon -spacecraft system
= - G M m / R where R is radius of orbit of spacecraft
kinetic energy of spacecraft in the orbit
= 1/2 m v² = GMm / 2R
Total energy of spacecraft
= GMm / 2R - G M m / R
= - GMm / 2R
for spacecraft to leave the orbit, energy required
= GMm / 2R
= 6.67259 x 10⁻¹¹ x 7.36 x 10²² x 14800 / (2 x 1.79877 x 10⁶)
= 202035.8 x 10⁵ J .
Answer:
The ball will reach the ground in 0.8s
Option C
Explanation:
Given:
- Takes t = 0.8 s for ball to reach ground when thrown horizontal from top of a building.
Find:
If it had been thrown with twice the speed in the same direction, it would have hit the ground in how many second.
Solution:
- We know that the amount of time taken to hit the ground is determined by the vertical distance i.e height at which it is thrown. The displacement of ball from top is given by:
S_y = S_o + V_i,y*t + 0.5*g*t^2
- We know that the S_o = height of the building.
We also know that the ball os thrown horizontally; hence, y-component of initial velocity is zero. V_y,i = 0
0 = h + 0 + 0.5*g*t^2
- Hence, the time taken t is:
t = sqrt ( 2h / g)
- The time taken to reach the ground is independent of the initial speed. Hence, the ball will reach the ground in 0.8s .
