Answer:
area = 5733.33 cm²
length = 5.47 ×
cm
Explanation:
Given data
density = 19.32 g/cm³
mass = 33.16 g
thickness = 3.000 µm = 3 ×
cm
radius r = 1.000 µm = 1 ×
cm
to find out
area of the leaf and length of the fiber
solution
we know volume formula that is
volume = mass / density
volume = 33.16 / 19.32
volume = 1.72 cm³
we know that volume = thickness × area
so area
area = volume / thickness
area = 1.72 / 3 ×
area = 5733.33 cm²
and
we know volume = πr²L
so L = volume / πr²
length = 1.72 / π(1×
)²
length = 5.47 ×
cm
Answer:
Explanation:
Given
time taken 
Speed acquired in 2 sec 
Here initial velocity is zero 
acceleration is the rate of change of velocity in a given time


Distance travel in this time

where
s=displacement
u=initial velocity
a=acceleration
t=time


so Jet Plane travels a distance of 42 m in 2 s
Answer:
1200 W
Explanation:
Power is given by the ratio between work done and time taken:

where W is the work done and t the time taken.
In this problem, W = 3600 J and t = 3.0 s. Therefore, the power in this exercise is

A wind turbine turns wind energy into electricity using the aerodynamic force
I can't eliminate answers. Some of them are just wrong. A is incorrect. There is no such thing as a 1 pole magnet.
I wouldn't use B. If it is just a bar it is not a magnet.
C is the traditional answer
D is a space filler. It is just there to occupy a letter.