The tub of a washing machine goes into its spin cycle, starting from rest and gaining angular speed steadily for 10.0 s, at which time it is turning at 6.00 rev/s. at this point, the lid of the washing machine is opened, and a safety switch turns it off. the tub then smoothly slows to rest in 13.0 s. through how many revolutions does the tub rotate while it is in motion?

69 revolutions

Explanation:

given,

initial angular velocity = 0

final angular velocity = 6 rev/s

when safety switch turned off

tub smoothly slows to rest in (t)= 13 s

total revolution of tub = ?

angular acceleration =

angular acceleration =

                                   = 0.6 rev/s²

now,

                 = 30 revolution

now,

when safety switch turn off

angular acceleration =

angular acceleration =

                                   = -0.462 rev/s²

now,

                 = 39 revolution

total revolution = 30 + 39 = 69 revolutions.

tub will rotate 69 revolutions

because growing process had stoped after 4-5 year

you'd use the equation that establishes a relationship between  energy  and  wavelength, which looks like this

e=h⋅cλ, where

λ  - the wavelength of the photon; c  - the speed of light, usually given as  3⋅108m/s; h  -  planck's constant, equal to  6.626⋅10−34j s

plug the value you were given for the energy of the photon in the above equation to get the wavelength

e=h⋅cλ⇒λ=h⋅ce

λ=6.626⋅10−34js⋅3⋅108ms−1.257⋅10−24j=1.581⋅10−1m