The relationship between frequency and wavelength for an electromagnetic wave is

where
f is the frequency

is the wavelength

is the speed of light.
For the light in our problem, the frequency is

, so its wavelength is (re-arranging the previous formula)
The right answer is B, the battery.
Answer:
a) 
b)
Explanation:
First we convert our minutes to hours so we work always in the same units.


Where we used the fact that 1 hour are 60 min, thus the multiplying factor is equal to 1 (not altering the time, just changing the units).
a) On the first part the motorist travels a distance
, and on the second part he travels
.
The total displacement is 
b) The average velocity is the relation between the total displacement and the time taken to cover it. Our total time is t=0.6h+0.25h+2.2h=3.05h, thus we have:

Answer:
6.429 m/s^2.
Explanation:
Using equations of motion,
i. vf = vi + at
ii. vf^2 = vi^2 + 2a*S
iii. S = vi*t + 1/2 * (a*t^2)
Where,
vf = final velocity of the motion
vi = initial velocity of the motion
S = distance travelled
t = time taken to complete the motion
a = acceleration due to gravity
Given:
vi = 0m/s
vf = 45 m/s
t = 7 s
a = ?
Using the i. equation of motion,
vf = vi + at
45 = 0 + a*7
a = 45/7
= 6.429 m/s^2