When they are in electron shells far from the nucleus.
The climate<span> was generally warmer and more humid than today, probably because of very active volcanism associated with unusually high rates of seafloor spreading.
</span><span>The first placental mammals appeared at the beginning of the Cretaceous. The Cretaceous saw the rise and extinction of the toothed birds, Hesperornis and Ichthyornis. The earliest fossils of birds resembling loons, grebes, cormorants, pelicans, flamingos, ibises, rails, and sandpipers were from the Cretaceous.</span>
Answer:
Explanation:
Given:
- wavelength of light in the air,
- time taken to travel from the source to the photocell via air,
- time taken to reach the photocell via air and glass slab,
- thickness of the glass slab,
<u>Now we have the relation for time:</u>
hence,
c= speed of light in air
For the case when glass slab is inserted between the path of light:
(since light travel with the speed c only in the air)
here:
v = speed of light in the glass
Using Snell's law:
Answer:
Upward: Negative
Downward: Positve
Explanation:
Let upward be positive
We want to find the work done on the object upwards.
The equation of work done due to gravity is
It is read as force of gravity times displacement times cos of the angle between the force and displacement.
Since gravity is happening down of the center of mass and the displacement is upwards, the angle is 180° so
Cosine of 180 is -1
so
If we go downwards, the sign will be positive because cos(0)=1
Answer: electric force and electric charge have an relationship, while electric force and distance have an relationship
Explanation: