A is the answer to your question
Answer:

Explanation:
The expression which represent the first diffraction minima by a circular aperture is given by
--------eqn 1
The angle through which the first minima is diffracted is given by
---------eqn 2
As
is very small so we can write 
So from eqn 1 and eqn 2 we can write
--------eqn 3
Here
is the position of first maxima D is the distance of screen from the circular aperture d is the diameter of aperture
It is given that diameter of circular aperture is 14.7 cm so 
Now putting all these value in eqn 3


Answer:
33.33 m/s
Explanation:
m = 450 kg. T = 5000 N, t = 3 seconds,
let the net acceleration is a.
T = m a
a = 5000 / 450 = 11.11 m/s^2
u = 0 , v = ?
Let v be the velocity after 3 seconds.
Use first equation of motion
v = u + a t
v = 0 + 11.11 x 3 = 33.33 m/s
A) The kinetic energy of an object is given by:

where m is the mass of the object, and v its speed. For the lion in our problem, m=45 kg and v=14.2 m/s, so its kinetic energy is

b) the increase in gravitational potential energy of the lion is given by:

where g is the gravitational acceleration, and

is the increase in altitude of the lion. In this problem,

, so the increase in gravitational potential energy is

c) When the fox reaches the top of the tree, its gravitational potential energy is

As it jumps, its kinetic energy is

So the total mechanical energy of the fox as it jumps is