The kinetic energy of the mass at the instant it passes back through its equilibrium position is about 1.20 J

<h3>Further explanation</h3>
Let's recall Elastic Potential Energy formula as follows:

where:
<em>Ep = elastic potential energy ( J )</em>
<em>k = spring constant ( N/m )</em>
<em>x = spring extension ( compression ) ( m )</em>
Let us now tackle the problem!

<u>Given:</u>
mass of object = m = 1.25 kg
initial extension = x = 0.0275 m
final extension = x' = 0.0735 - 0.0275 = 0.0460 m
<u>Asked:</u>
kinetic energy = Ek = ?
<u>Solution:</u>
<em>Firstly , we will calculate the spring constant by using </em><em>Hooke's Law</em><em> as follows:</em>






<em>Next , we will use </em><em>Conservation of Energy</em><em> formula to solve this problem:</em>







<h3>Learn more</h3>

<h3>Answer details</h3>
Grade: High School
Subject: Physics
Chapter: Elasticity
When Emmett is lifting a box
vertically, the forces that must be added to calculate the total force are: the
gravitational force, tension force(the force exerted by Emmett to the box and
the force exerted by the box to Emmett), and air resistance force.
The expression for the block's centripetal acceleration is derived as ω²r or v²/r.
<h3>
What is centripetal acceleration?</h3>
The centripetal acceleration of an object is the inward or radial acceleration of an object moving in a circular path.
The expression for the block's centripetal acceleration is derived as follows;
ω = dθ/dt
where;
- ω is the angular speed
- θ is the angular displacement
- t is the time of motion
ac = ω²r
where;
- r is the radius of the circular path
Also, ω = v/r
ac = (v/r)²r
ac = v²/r
Thus, the expression for the block's centripetal acceleration is derived as ω²r or v²/r.
Learn more about centripetal acceleration here: brainly.com/question/79801
Vf=V1+at
0=31+a(7)
-31/7=a
a=-4.43m/s^2
Hope this helps.
The star is the main sequence