Solve Simple Oscillation Homework: Find Max Kinetic Energy (mJ)

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The discussion focuses on calculating the maximum kinetic energy of a body oscillating on a spring with a spring constant of 3.5 N/m. The equation of motion provided is y = (4.5 cm) sin [(0.62 rad/s)t], and the formula for maximum kinetic energy is Kmax = 0.5kA^2. The user calculated Kmax as 0.003543 J but faced issues with the answer not being accepted, suspecting a machine error. Clarification on units indicates that 1 mJ equals 10^-3 J, leading to confusion about the conversion of joules to millijoules. The thread highlights the importance of correct unit conversion in physics problems.
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Homework Statement


A body is suspended vertically from an ideal spring of spring constant 3.5 N/m. The spring is initially in its relaxed position. The body is then released and oscillates about its equilibrium position. The motion is described by the following equation.

y = (4.5 cm) sin [(0.62 rad/s)t]

What is the maximum kinetic energy of the body?
[answer in mj)


Homework Equations



Kmax=.5kA^2

The Attempt at a Solution



.5(3.5)(.045)^2=.003543 J but the answer must be in mj. So, 3.543x10^-9 BUT computer did not accept the answer as a correct one... Could anyone help me please?
Thanks!
 
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1 mJ equal to how many Joules?
 
.003543 joules = 3.54300 × 10-9 megajoules
so if my answer is correct, then it is the machine error that it's not being accepted. is my answer correct?
Thanks
 
jeunesse27 said:
.003543 joules = 3.54300 × 10-9 megajoules
so if my answer is correct, then it is the machine error that it's not being accepted. is my answer correct?
Thanks
mJ is milli joule i.e. 10^-3 J. Mega Joule is MJ = 10^6 J
 
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