Answer:d
Explanation:
Drift velocity is given by

where
=drift velocity
I=Current
n=no of electron
Q=charge of Electron
A=cross-section
If area of cross-section decreases gradually then drift velocity will increase because drift velocity is inversely proportional to Area of cross-section
Ep=mgh
h= Ep/mg
h=57÷(3.3×9.8)
h= 57÷32.34
h= 1.8m
So; the answer is B. 1.8m
Answer:

Explanation:
initially the merry go round is at rest
after 6.73 s the merry go round will accelerates to 20 rpm
so final angular speed is given as



so final tangential speed is given as


now average acceleration of the girl is given as



Answer:
The terminal velocity is 
Explanation:
From the question we are told that
The mass of the squirrel is 
The surface area is 
The height of fall is h =4.8 m
The length of the prism is 
The width of the prism is 
The terminal velocity is mathematically represented as

Where
is the density of a rectangular prism with a constant values of 
is the drag coefficient for a horizontal skydiver with a value = 1
A is the area of the prism the squirrel is assumed to be which is mathematically represented as


substituting values

