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3 years ago

I need help on both questions

Physics

2 answers:

saw5 [17]3 years ago

6 0

20 until 40 not moving
other with out 20 until 40 is moving

iris [78.8K]3 years ago

3 0

It's not in motion when the line straight and flat . there's #9

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Will give brainliest to right answer!

viva [34]

The correct answer is D.

8 0

3 years ago

he fan blades on a jet engine make one thousand revolutions in a time of 54.9 ms. What is the angular frequency of the blades?

Gnesinka [82]

So, the angular frequency of the blades approximately <u>36.43π rad/s</u>.

<h3>Introduction</h3>

Hi ! Here I will discuss about the angular frequency or what is also often called the angular velocity because it has the same unit dimensions. <u>Angular frequency occurs, when an object vibrates (either moving harmoniously / oscillating or moving in a circle)</u>. Angular frequency can be roughly interpreted as the magnitude of the change in angle (in units of rad) per unit time. So, based on this understanding, the angular frequency can be calculated using the equation :

$\boxed{\sf{\bold{\omega = \frac{\theta}{t}}}}$

With the following condition :

$\sf{\omega}$ = angular frequency (rad/s)
$\sf{\theta}$ = change of angle value (rad)
t = interval of the time (s)

<h3>Problem Solving</h3>

We know that :

$\sf{\theta}$ = change of angle value = 1,000 revolution = 1,000 × 2π rad = 2,000π rad/s >> Remember 1 rev = 2π rad/s.
t = interval of the time = 54.9 s.

What was asked :

$\sf{\omega}$ = angular frequency = ... rad/s

Step by step :

$\sf{\omega = \frac{\theta}{t}}$

$\sf{\omega = \frac{2,000 \pi}{54.9}}$

$\boxed{\sf{\omega \approx 36.43 \pi \: rad/s}}$

<h3>Conclusion :</h3>

So, the angular frequency of the blades approximately 36.43π rad/s.

8 0

2 years ago

A small 20-kg canoe is floating downriver at a speed of 2 m/s. What is the canoe’s kinetic energy? A. 40 J B. 80 J C. 18 J

rusak2 [61]

A small 20-kg canoe is floating downriver at a speed of 2 m/s. 40 J is the canoe’s kinetic energy.

Answer: Option A

<u>Explanation:</u>

The given canoe has the mass and is being given to move at a speed. Therefore the kinetic energy of the canoe can be calculated using the following method,

Given that mass of the canoe = 20 kg and its speed =1 m/s

As we know that the Kinetic energy has the formula,

$\text {Kinetic energy}=\frac{1}{2} \boldsymbol{m} \boldsymbol{v}^{2}$

Therefore, substituting the value into the equation, we get,

$K . E .=\frac{1}{2} \times 20 \times 2^{2}$ = 40 J

4 0

3 years ago

Read 2 more answers

Acceleration is often measured in what unit? A. newtons B. kilograms C. meters per second D. meters per second squared

spayn [35]

D. meters per second squared

3 0

3 years ago

Read 2 more answers

Which of the following represents the greatest energy transition from a higher energy level to a lower one?

prohojiy [21]

You need to use Planck's law:
E = h·υ = (h·c)/λ

Without making all the calculations, a fraction is bigger than another when the denominator is smaller. Therefore you need to find the smallest wavelength (λ) which is 450nm.

You could also be helped by colors: in order of decreasing energy, you have blue - green - yellow - red.

In any case, the correct answer is a).

8 0

3 years ago