Answer: 4.98 m/s
Explanation:
You solve these kinetic energy, potential energy problems by using the fact P.E.+ K.E. = a constant as long as friction is ignored.
PEi = 0 in this case
KEi = ½mVi² = PEf+KEf = mghf + ½mVf²
½1210*8.31² = 1210*9.8*2.26 + ½1210*Vf²
½1210*Vf² = ½1210*8.31² - 1210*9.8*2.26
Vf² = 8.31² - 2*9.8*2.26 = 4.98² so Vf = 4.98m/s
In a double-slit interference experiment, the distance y of the maximum of order m from the center of the observed interference pattern on the screen is

where D=5.00 m is the distance of the screen from the slits, and

is the distance between the two slits.
The fringes on the screen are 6.5 cm=0.065 m apart from each other, this means that the first maximum (m=1) is located at y=0.065 m from the center of the pattern.
Therefore, from the previous formula we can find the wavelength of the light:

And from the relationship between frequency and wavelength,

, we can find the frequency of the light:
Answer:
15.8 seconds
Explanation:
Create an extended calculation to convert all the unit to what you need.
160 km 1000 m 1 hour 1 min
----------- x ------------- x -------------- x ---------- = 44.4 m/s
1 hour 1 km 60 min 60 sec
So 160km/hr is equal to 44.4m/s
Now you can figure out how many seconds it will take to go 700 meters.
44.4 m
---------- X x sec = 700 m
1 sec
Solve for x sec
x sec = 700m / 44.4 m/s
= 15.8 seconds
Work done is the distance a force acts over.
So, the work done here is 9.0N * 3.0m = 27 J
B. I think is the correct answer