The first three choices: a, b and c can be considered reconstruction except the last one which is letter d. I'm not really certain what reconstruction is, but judging from the patterns of the first three choices, reconstruction could mean that an inference is made after a part of an event has proved that event to be true.
Answer:
The magnetic flux through the desk surface is
.
Explanation:
Given that,
Magnetic field B = 0.42 T
Angle =68°
We need to calculate the magnetic flux

Where, B = magnetic field
A = area
Put the value into the formula



Hence, The magnetic flux through the desk surface is
.
Answer:
The Forces of Flight
At any given time, there are four forces acting upon an aircraft.
These forces are lift, weight (or gravity), drag and thrust. Lift is
the key aerodynamic force that keeps objects in the air. It is the
force that opposes weight; thus, lift helps to keep an aircraft in
the air. Weight is the force that works vertically by pulling all
objects, including aircraft, toward the center of the Earth. In order
to fly an aircraft, something (lift) needs to press it in the opposite
direction of gravity. The weight of an object controls how strong
the pressure (lift) will need to be. Lift is that pressure. Drag is a
mechanical force generated by the interaction and contract of a
solid body, such as an airplane, with a fluid (liquid or gas). Finally,
the thrust is the force that is generated by the engines of an
aircraft in order for the aircraft to move forward.
Explanation:
Given that the function of the wave is f(x) = cos(π•t/2), we have;
a. The graph of the function is attached
b. 4 units of time
c. Even
d. 4.935 J/kg
e. 1.234 W/kg
<h3>How can the factors of the wave be found?</h3>
a. Please find attached the graph of the signal created with GeoGebra
b. The period of the signal, T = 2•π/(π/2) = <u>4</u>
c. The signal is <u>even</u>, given that it is symmetrical about the y-axis
d. The energy of the signal is given by the formula;

Which gives;
E = 0.5 × 1.571² × 1² × 4 = <u>4.935 J/kg</u>
e. The power of the wave is given by the formula;
E = 0.5 × 1.571² × 1² × 4 × 0.25 = <u>1.234 W/</u><u>kg</u>
Learn more about waves here:
brainly.com/question/14015797
Answer:
F₁ = 4 F₀
Explanation:
The force applied on the string by the ball attached to it, while in circular motion will be equal to the centripetal force. Therefore, at time t₀, the force on ball F₀ is given as:
F₀ = mv₀²/r --------------- equation (1)
where,
F₀ = Force on string at t₀
m = mass of ball
v₀ = speed of ball at t₀
r = radius of circular path
Now, at time t₁:
v₁ = 2v₀
F₁ = mv₁²/r
F₁ = m(2v₀)²/r
F₁ = 4 mv₀²/r
using equation (1):
<u>F₁ = 4 F₀</u>