What Is the Maximum Speed in This Simple Harmonic Motion Problem?

[koat]

A mass between 2 springs moves with shm.
it oscillates between 2 points 5cm apart and completes 40 oscillations in 1min
whats its max speed?

Please help i always get the wrong answer
The answer is 0.44 but why?

 

[gneill]

A mass between 2 springs moves with shm.
it oscillates between 2 points 5cm apart and completes 40 oscillations in 1min
whats its max speed?

Please help i always get the wrong answer
The answer is 0.44 but why?

Show your solution attempt. We can't tell what's going wrong if we don't see what you're doing.

 

[koat]

2pi*40/60= 4/3 pi
f= 4/3pi*1/2= 2/3
vmax= 2pi*2/3*2.5*10^-2
but the answer is wrong :(

 

[gneill]

2pi*40/60= 4/3 pi
f= 4/3pi*1/2= 2/3
vmax= 2pi*2/3*2.5*10^-2
but the answer is wrong :(

Actually, your answer is correct. Looks like the answer key is wrong

You've correctly calculated the frequency of the oscillations:

$A = 5 cm/2$

$f = 40 cycles/min$

$\omega = \frac{40 cycles}{min} \times \frac{1\;min}{60\;sec} \times \frac{2 \pi \; rad}{cycle} = \frac{4}{3}\pi \frac{rad}{sec}$

$v = A \omega = \frac{10 \pi}{3}\frac{cm}{sec} = 0.105 m/s$