To increase the distance of the first dark fringe from the central maximum in a single-slit diffraction
pattern, you should
(a) use more intense light
(b) use light of a higher frequency
(c) use light of a longer wavelength
(d) replace the slit with a wider opening
explain

diagram is missing, but i will try to explain your doubt.

answer:

amplitude is the maximum displacement or distance moved on a point of a vibrating body or wave measured from its equilibrium position.it is equal to half the length of vibration path.

acceleration = (change in speed) / (time for the change)

change in speed = (20-120)= -100 m/s.

1.5 min = 90 sec

acceleration = -100/90 = -1.11 m/s^2.

we don't care about the 150kg or the 2,500 meters. they don't make any difference.

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the answer would be 32*f