Homework Help: Spring help-please

1. Dec 8, 2003

bard

At t=0, a 650-g(0.65kg) mass at rest on the end of a horizontal spring(k=184n/m) is struck by a hammer which gives it an initial speed of 2.26 m/s. Determine (a) the period and frequency of the motion (b)the amplitude (c)the maximum acceleration (d) the position as a function of time (e) the total energy, and (f)the kinetic energy when x=0.4A where A is the amplitude.

a) period=2pi*sqrt0.65/184=.37
Frequency=2.07
b)v=sqrtk/m(A^2-X^2)=0.13

C) A-max=184*0.13/0.65=36.8 m/s^2

d)x=0.13cos(phi)

e)no idea

f)no idea

2. Dec 8, 2003

himanshu121

Revisit the formula for Total energy and K.E.

Total Energy remains Constant

3. Dec 8, 2003

bard

so the total energy would be

1/2 KA^2

4. Dec 9, 2003

himanshu121

yes and what about the K.E.

5. Dec 9, 2003

HallsofIvy

Two other points:

I get that the frequency is 2.70 not 2.07. A typo?

The position, measured from the rest point, is .13 sin(16.8t).

There was no "phi" in the problem. What was that?

6. Dec 9, 2003

bard

So the kinetic energy would be

1/2*184(0.052)^2=.25J

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