Answer: The box was moving with a velocity of 0.256m/s when it hit the spring
Explanation: Please see the attachments below
Through a dam... hope this helps:)
This actually means that the object which is emitting light spectrum is moving away from us.. how do you know that ? well.. it is clearly mentioned that it is a red shift so the wavelengths will stretched more . and thus the spectrum turns more reddish as it has higher wavelengths .. hence so called red shifts