Answer:
Part a)
f = 1911.5 Hz
Part b)

Explanation:
Here the source and observer both are moving towards each other
so we know that the apparent frequency is given as

here we know that



now we will have


Part b)
Apparent wavelength is given by the formula

here we will have


D:the electrons from being attracted to the grid instead of the anode
We use the equation of motion,

Here, S is the height, u is initial velocity and a is acceleration.
Given,
As acorn falls from tree, therefore we take the value of
and initial velocity
.
Substituting these values in equation of motion,

Thus, the time taken by the acorn to fall 20 feet ( 6.096 m ) is 1.12 s.
I'm really not sure if this is right but I'll try.
The distance that the dog traveled is probably all of the distances added up. I would guess that it's 67 meters in total.
The displacement is a little more tricky but you pretty much have to put a mental map in your head. Since East and West are both 8 meters, they cancel each other out. He travels more southern and that means the displacement is 9 meters south of his original location
Answer:
T = 60 s
Explanation:
There are 6 poles on the track which are equally spaced
so the angular separation between the poles is given as


so the angular speed of the train is given as


now we have time period of the train given as


