Answer:
a. 30 N / m
b. 9.0 N
Explanation:
Given that
Unstretched length of the spring, 
= 20.0cm = 0.2m
a) When the mass of 4.5N is hanging from the second spring, then extended length Is
= 35.0cm = 0.35m
So, the change in spring length when mass hangs is
= (0.35 - 0.20) m
= 0.15m
As spring are identical
Let us assume that the spring constant be "k", so at equilibrium
Restoring Force on spring = Block weightage
kx = W = 4.50
= 30 N / m
b) Now for the third spring, stretched the length of spring is
= 50cm = 0.5m
So, the change in spring length is
= (0.5-0.20)m
= 0.30m
At equilibrium,
Restoring Force on spring = Block weightage
Now using all mentioned and computed values in above,
= 30(0.3)
= 9.0 N
Myofibrils are composed of long proteins such as actin, myosin, and titin, and other proteins that hold them together. These proteins are organized into thin filaments and thick filaments, which repeat along the length of the myofibril in sections called sarcomeres. Muscles contract by sliding the thin (actin) and thick (myosin) filaments along each other.
Answer:
a) factor 
b) factor 
c) factor 
d) factor
Explanation:
Time period of oscillating spring-mass system is given as:
where:
frequency of oscillation
mass of the object attached to the spring
stiffness constant of the spring
a) <u>On doubling the mass:</u>
- New mass,
<u>Then the new time period:</u>
where the factor as asked in the question.
b) On quadrupling the stiffness constant while other factors are constant:
New stiffness constant, 
<u>Then the new time period:</u>
where the factor as asked in the question.
c) On quadrupling the stiffness constant as well as mass:
New stiffness constant,
New mas, 
<u>Then the new time period:</u>
where factor as asked in the question.
d) On quadrupling the amplitude there will be no effect on the time period because T is independent of amplitude as we can observe in the equation.
so, factor
Answer:
As the person moves down the zip wire, her increase in kinetic energy is less than her decrease in gravitational potential energy.
Explanation:
Work is done against the air resistance, causing thermal energy to transfer to the surroundings
Answer:
Earth's axis is tilted relative to its orbital plane.
Earth orbits around the Sun, completing one orbit each year
Explanation:
The earth tilt at an angle causes the sun rays to hit the earth surface around the globe differently. Due to the oblique angle that the rays hit the subtropics and poles, there is less heat intensity compared to the equator where the sun rays hit the earth's surface at a more or less right angle.
The earth rotation around the sun also causes seasons coupled with the earth’s tilts. As the earth rotates, in one point in the orbit, the northern or southern hemispheres will be tilted towards the sun. The phenomenon varies the local temperatures of particular regions of the earth hence driving seasonal climatic changes.
