Answer:
+7.0 m/s
Explanation:
Let's take rightward as positive direction.
So in this problem we have:
a = -2.5 m/s^2 acceleration due to the wind (negative because it is leftward)
t = 4 s time interval
v = -3.0 m/s is the final velocity (negative because it is leftward)
We can use the following equation:
v = u + at
Where u is the initial velocity
We want to find u, so if we rearrange the equation we find:

and the positive sign means the initial direction was rightward.
Answer:

Explanation:
Give that,
The potential difference of the electrons, 
We need to find the wavelength of the electrons.
Using the conservation of energy,

Put all the values,

So, the wavelength of the electrons is
.
Answer:
517.5Ns
Explanation:
F=(MV - MU)/t
where MV - MU is the change in momentum,
therefore, MV - MU = Ft
= 345 X 1.
= 517.5Ns
Answer:
i'm pretty sure its B but i may be wrong if you dont wanna take the chance wait for someone
Explanation:
The answer is C. elastic potential energy