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


Gravity pulls to the centre of the earth. A ship floats in water because the water pushing it up (upthrust) is equal to the force<span> of gravity (weight) pulling it </span>down<span>. Friction also occurs when objects move through air. This is </span>called<span>air resistance.</span>
Answer:
Explanation:
See the attached figure . See the forces acting on man pulling up the box .
Man is stationary so net force acting on man is zero .
T + R = Wman
R is the reaction force of the ground of second floor .
R = Wman - T
The correct answer among the choices given is option B. The energy transformation that occurs in the core of a nuclear reactor is from nuclear energy to thermal energy. In a power plant nuclear fission which involves nuclear energy to heat up water around it. This part is the core of the process.
Explanation:
Acceleration is the change in speed over change in time.
a = Δv / Δt
a. The car's acceleration is:
a = (80 km/h − 0 km/h) / 10 s
a = 8 km/h/s
So every second, the speed increases by 8 km/h.
b. The cyclist's acceleration is:
a = (16 m/s − 4.0 m/s) / 5.6 s
a = 2.1 m/s²
c. The stone's speed is:
10.0 m/s² = (v − 0 m/s) / 3.5 s
v = 35 m/s
d. The time is:
1.6 m/s² = (10 m/s − 0 m/s) / t
t = 6.3 s