semiconductors ... silicon, germanium etc ...
I believe you ask about speed at the end of the hose:
The volume of the bucket is 225 liters which is equal to 225

.

Hose's cross section can be counted with the typical circle's area formula (with diameter instead of radius, that's why you've got a fraction):


are filled within 15 second.
As the bucket is being filled you can say that it's volume is the volume of the water that flowed out of the hose, then:

The speed of the water can be counted with equation:

After extracting h from the volume's equation you get:

When you count the fraction you get the answer:
Answer:
angular range is ( 0.681 rad , 0.35 rad )
Explanation:
given data
wavelength λ = 380 nm = 380 ×
m
wavelength λ = 700 nm = 700 ×
m
to find out
angular range of the first-order
solution
we will apply here slit experiment equation that is
d sinθ = m λ ...........1
here m is 1 for single slit and d is = 
so put here value in equation 1 for 380 nm
we get
d sinθ = m λ
sinθ = 1 × 380 × 
θ = 0.35 rad
and for 700 nm
we get
d sinθ = m λ
sinθ = 1 × 700 × 
θ = 0.681 rad
so angular range is ( 0.681 rad , 0.35 rad )