# 7 the answer is 4) because you need opposites in order to attract
# 8 I'm going to guess it is 4) because electricity is needed in order a light bolt to work.(don't take my word for this one I'm not sure but, the other answer are correct)
# 9 the answer is 4) because the comb dose collect negative charges from the hair in order to make the hair have positive charge.
Hope this helped : )
I would assume air resistance is negligible and so the acceleration of the package would be approximately 9.81 m/s².
Taking downwards as positive, use v²=u²+2as.
v²=(-2)²+2(9.81)(14)
v=16.7 m/s
Answer:
Use a faster than normal approach and landing speed.
Explanation
For pilots, it is one of the critical moments of the flight that concentrates 12% of fatal accidents. The main difficulty lies in reaching enough speed to take flight within the space of the runway. At present, it ceased to be a challenge for the aircraft, since the engine power improved, so the takeoff ceased to be the most dangerous moment of the flight.
One of the risks that aircraft face today is that some of the engines fail while the plane accelerates. In that case, the pilot must decide in an instant whether it is better to take flight and solve the problem in the air or if it is preferable not to take off.
Although for many staying on the ground might seem the most sensible option, it is not as simple as it seems: to suddenly decelerate an aircraft, with the weight it has and the speed it reaches can cause accidents. However, today a special cement was designed that runs around the runways of the airports, which when coming into contact with the wheels of the aircraft the ground breaks and helps to slow down.
Frequency decreases whilst wavelength increases and the opposite also occurs
The answer is λ₂ = 6.48 cm or 6.52 cm.
The out-of-tune guitar may have a wavelength between "6.48 cm" and "6.52 cm."
fb = |f2 − f1|
f₁ = 343/0.064
= 5276Hz
f₂ = 5276.9 Hz ± 17 Hz
f₂ = 5293.9 Hz or 5259.9 Hz
Now, calculating the possible wavelengths:
λ = 343/ 5259.9 or 343/ 5293.9
λ₂ = 6.48 cm or 6.52 cm
<h3>Why is beat frequency important?</h3>
When two waves with almost identical frequencies traveling in the same direction collide at a certain location, beats are produced. The opposing beneficial and harmful disruption causes the sound to alternatively be loud and weak whenever two sound waves with different frequencies reach your ear. This is referred to as beating.
The entire value of the frequency difference between the two waves is the beat frequency.
The following formula yields the beat frequency:
fb = |f2 − f1|
Learn more about beat frequency here:
brainly.com/question/14705053
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