Let the distance between the towns be d and the speed of the air be s.
distance = speed * time
convert the minutes time into hours.
When flying into the wind, ground speed will be air speed MINUS wind speed, hence the against the wind trip is described by:
d
s−15
=
7
3
return trip is then :
d
s+15
=
7
5
Cross-multiplying both we get the two-variable system:
3d=7∗(s−15)5d=7∗(s+15)
3d=7s−1055d=7s+105
subtract first equation from second equation we get
2d=210d=105km
Substitute the value of d in the above equations for s.
5∗105=7s+1057s=420s=60km/hr
A) 750 m
First of all, let's find the wavelength of the microwave. We have
is the frequency
is the speed of light
So the wavelength of the beam is

Now we can use the formula of the single-slit diffraction to find the radius of aperture of the beam:

where
m = 1 since we are interested only in the central fringe
D = 30 km = 30,000 m
a = 2.0 m is the aperture of the antenna (which corresponds to the width of the slit)
Substituting, we find

and so, the diameter is

B) 0.23 W/m^2
First we calculate the area of the surface of the microwave at a distance of 30 km. Since the diameter of the circle is 750 m, the radius is

So the area is

And since the power is

The average intensity is

D. a and c
Explanation:
To make a generator out of a bicycle, Devon will need two magnets and coil of wire.
There is a close knit relationship between magnetism and electricity. Electricity can be generated by a wire changing flux in the presence of a magnetic field.
- The magnets provide magnetic field for the process.
- The coil of wire is placed in between the magnetic field generated by the magnets.
- The bicycle pedal is connected to the set up to turn the wire in between the magnetic fields.
- This way, electricity is produced.
Learn more:
Electromagnet brainly.com/question/2191993
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Answer:
The distance by the ball clear the crossbar is 1.15 m
Explanation:
Given that,
Distance = 44 m
Speed = 24 m/s
Angle = 31°
Height = 3.05 m
We need to calculate the horizontal velocity
Using formula of horizontal velocity

Put the value into the formula


We need to calculate the vertical velocity
Using formula of vertical velocity

Put the value into the formula


We need to calculate the time
Using formula of time

Put the value into the formula


We need to calculate the vertical height
Using equation of motion

Put the value into the formula


We need to calculate the distance by the ball clear the crossbar
Using formula for vertical distance

Put the value of h


Hence, The distance by the ball clear the crossbar is 1.15 m
Answer: The SI unit
Explanation: The SI units are used to describe the distance an object moves