<span>Partyrockchickk is on the right track,
but 23:56:04 is not exactly exact.
23h 56m 4.0906s is closer, but still
not exact. You'll never see an 'exact'
number written anywhere. First
because it doesn't work out to an exact
decimal of anything, and second
because it changes ! The Good Friday
earthquake in Alaska changed it,
the Fukushima earthquake changed it,
the Nepal earthquake changed it,
and the daily drag of the tides changes
it by something like 0.001
second every century.
One thing's for sure: It is definitely <em><u>not </u></em>24 hours.
</span>
Answer:
Option B is the correct answer.
Explanation:
Shear stress is the ratio of shear force to area.
We have
Shear stress = 3 N/mm² = 3 x 10⁶ N/m²
Area = Area of rectangle = 10 x 10⁻² x d = 0.1d
Shear force = 50000 N
Substituting
Width of beam = 16.67 cm
Option B is the correct answer.
In atoms, electrons surround the nucleus in specific energy levels.
Answer: Option B
<u>Explanation:
</u>
Atom, actually considered as the tiny part that is ever present in this universe. Many theories and experiments were conducted, for studying what was present inside of an atom, and many theories came into light.
And finally, Bohr-Sommerfeld Theory stated the final conclusion, that the positive charge is at the centre of the nucleus, and all the electrons revolve in their specific energy levels. If an atom wants to move to lower energy state, it should emit energy, whereas for going to higher state, it should gain energy.
The answers are as follows:
64. SKELETAL MUSCLES
Body location: it is usually attached to the bone or to the skin.
Microscopic anatomy: it is made up of very long, cylindrical multinucleated cells which are striated.
Regulation of contraction: the nervous system controls the voluntary contraction of the skeletal muscles.
Speed of contraction: the speed of contraction ranges from slow to fast.
Rhythmicity: the skeletal muscle is arrhythmic.
SMOOTH MUSCLES
Body location: found in the wall of hollow visceral organs [not including those of the heart].
Microscopic anatomy: made up of single fusiform, uninucleated cells that are without striation.
Regulation of contraction: smooth muscles undergo involuntary contractions which are controlled by the nervous system and hormones.
Speed of contraction: very slow. it is the slowest of the three muscles.
Rhythmicity: rhythmic.
CARDIAC MUSCLES
Body location: located in the wall of the heart.
Microscopic anatomy: it is composed of branching chains of cells, that are uninucleated; they are striated and posses intercalated discs.
Regulation of contraction: Undergo involuntary contractions, which are controlled by nervous system, heart pacemarker and hormones.
Speed of contraction: slow.
Rhythmicity: rhythmic.
65. Aging brings about gradual loss in muscle functions. As one grows older, there are usually age related alterations in the skeletal muscle functions. The factors that affect the rate of muscle loss are sex and level of muscle activity. Loss of muscle mass also occurs as one grows older.
66. The sliding filament theory states that, during contraction the thin filaments slide past the thick filaments and the sacomere shortens.
During contraction, the myosin head attaches to the myosin binding site on the actin filament. Using energy from ATP, the myosin head move toward the center of the sacomere, attaching and detaching several times. As a result of this, the thin actin filament is pulled toward the center of the sacomere. This leads to the shorten of the muscle cells.
Answer:
Explanation:
1. The net force acting on an object is the combination of all of the individual forces acting on it.
2. If two forces act on an object in opposite directions, the net force is the difference between the two forces.
3. If two forces act on an object in the same direction, the net force is the sum of the two forces.