I need to know how to solve a problem like this, Please show the equations used

Question

I need to know how to solve a problem like this, Please show the equations used and the process.

3. A spring that does not conform to Hooke's Law has a force whose magnitude is given by F (6x2 +2x)N with its direction opposite to the displacement of the spring. One end of the spring is attached to a support and a 2kg mass is suspended from the other end. The mass is raised so that the spring is un-stretched and released from rest. How fast (in m/s) is the mass traveling after it has fallen 1.00m? (15 points). Ans. 4.07m/s

Explanation / Answer

F = 6 x^2 + 2 x

Work done by spring, W = - F.dx

W = - (2 x^3 + x^2 )

putting x = 1

W = - 3 J

Work done by gravity = m g h = 2 x 9.81 x 1= 19.62 J

Applying work - energy theorem

Net work done = change in KE

19.62 - 3 = 2 v^2 /2

v = 4.08 m/s .........Ans

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---