Answer:
Fg = 98.1 [N]; N = 98.1 [N]; Ff = 39.24 [N]; a = 2.076[m/^2]
Explanation:
To solve this problem, we must make a free body diagram and interpret each of the forces acting on the box. In the attached diagram we can find the free body diagram.
The gravitational force is equal to:
Fg = (10 * 9.81) = 98.1 [N]
Now by summing forces on the Y axis equal to zero, we can find the normal force exerted by the surface.
N - Fg = 0
N = Fg
N = 98.1 [N]
The friction force is defined as the product of normal force by the coefficient of friction.
Ff = N * μ
Ff = 98.1 * 0.4
Ff = 39.24 [N]
By the sum forces on the x-axis equal to the product of mass by acceleration (newton's second law), we can find the value of acceleration.
60 - Ff = m * a
60 - 39.24 = 10 * a
a = 2.076[m/^2]
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:
Covalent bonding occurs when pairs of electrons are shared by atoms. Atoms will covalently bond with other atoms in order to gain more stability, which is gained by forming a full electron shell. By sharing their outer most (valence) electrons, atoms can fill up their outer electron shell and gain stability.
Explanation:
The power developed by the student is 756.9 J/s and remains the same if the student takes the same time to climb the stairs when climbing it in two's and three's.
<h3>What is power?</h3>
Power is the rate at work is done.
- Power = work done/time
- work done = mass × acceleration due to gravity × height
Work done = 65.5 × 10 × (18 × 0.165) = 1945.35 J
Power = 1945.35/2.57 = 756.9 J/s
If the student climbed the steps in two or three at a time, the power does not change if the time remains the same.
- Time required = Energy/ power
The time required to convert the Big Mac meal from McDonalds = 4 853 440/756.9
Time required = 6412.26 seconds
Therefore, from the power developed by the student, it will take him 6412.26 seconds to convert all the energy in a Big Mac meal.
Learn more about power at: brainly.com/question/1634438
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If you're calculating the power of an athlete who is lifting weights,
or the power of a windmill that is pumping water from a well, or
the power of two horses turning millstones, then those electrical
units won't help at all.
But if you happen to be calculating the power delivered to an
electrical circuit or dissipated by an electrical device, then you
can use ...
(voltage) times (current)
or
(voltage)² divided by (resistance)
or
(current)² times (resistance) .
The choice just depends on which quantities you know
or can easily measure.