Answer:
False
In a phase contrast microscope, the phase plate causes diffracted light waves to undergo a phase shift by 1/2 wavelength.
Explanation:
Phase contrast microscope is dependent on the difference in refracting index from object to surrounding. Light beam passes through the organism and it gets refracted through it. The phase change is difference in the refracting index of the two medium through which light passes.
Thus, the diffracted beam of light causes the phase shift by 1/2 wavelength.
<span>The amount of energy carried by a wave is proportional to the square of the wave’s amplitude. The amplitude is measured by calculating the distance from the top (or bottom) of the wave and the middle or center.</span>
Answer:
The direction of the field is downward, and negatively charged particles will experience an upwards force due to the field.
F = N e E where E is the value of the field and N e the charge Q
M g = N e E and M g is the weight of the drop
N = M g / (e E)
N = 1.1E-4 * 9.8 / (1.6E-19 * 370) = 1.1 * 9.8 / (1.6 * 370) * E15 = 1.82E13
.00011 kg is a very large drop
Q = N e = M g / E = .00011 * 9.8 / 370 = 2.91E-6 Coulombs
Check: N = Q / e = 2.91E-6 / 1.6E-19 = 1.82E13 electrons
Answer:
The evolutionary lineage of the horse is among the best-documented in all paleontology. The history of the horse family, Equidae, began during the Eocene Epoch, which lasted from about 56 million to 33.9 million years ago. During the early Eocene there appeared the first ancestral horse, a hoofed, browsing mammal designated correctly as Hyracotherium but more commonly called Eohippus, the “dawn horse.” Fossils of Eohippus, which have been found in both North America and Europe, show an animal that stood 4.2 to 5 hands (about 42.7 to 50.8 cm, or 16.8 to 20 inches) high, diminutive by comparison with the modern horse, and had an arched back and raised hindquarters. The legs ended in padded feet with four functional hooves on each of the forefeet and three on each of the hind feet—quite unlike the unpadded, single-hoofed foot of modern equines. The skull lacked the large, flexible muzzle of the modern horse, and the size and shape of the cranium indicate that the brain was far smaller and less complex than that of today’s horse. The teeth, too, differed significantly from those of the modern equines, being adapted to a fairly general browser’s diet. Eohippus was, in fact, so unhorselike that its evolutionary relationship to the modern equines was at first unsuspected. It was not until paleontologists had unearthed fossils of later extinct horses that the link to Eohippus became clear.
evolution of the horse
Eohippus
evolution of the horse
Evolution of the horse over the past 55 million years. The present-day Przewalski's horse is believed to be the only remaining example of a wild horse—i.e., the last remaining modern horse to have evolved by natural selection. Numbered bones in the forefoot illustrations trace the gradual transition from a four-toed to a one-toed animal.
Eohippus
Eohippus, in an artist's conception. Existing toe bones of the forefoot are numbered outward from the centre of the body. Officially, taxonomists have classified this extinct mammal, which is considered to be the first known horse, in the genus Hyracotherium.