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2 years ago

List 2 examples of objects demonstrating mechanical energy.

1 answer:

6 0

Windmills run on the principle of mechanical energy and work. Moving air (wind) possesses some amount of energy in the form of kinetic energy (due to motion). This energy gives the air the ability to do work on the blades of the fan.

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A turntable that spins at a constant 80.0 rpmrpm takes 3.50 ss to reach this angular speed after it is turned on. Find its angul

Veronika [31]

Answer:

The angular acceleration is 2.39 rad/s².

The number of degrees it rotates is 841.68 degrees.

Explanation:

Given:

Initial angular speed (ω₀) = 0 rad/s

Final angular speed in rpm (N) = 80.0 rpm

Time taken (t) = 3.50 s

First, let us determine the final angular speed in radians per second.

We know that,

$\omega=\frac{2\pi N}{60}\ rad/s$

Plug in the values and find the final angular speed, 'ω'. This gives,

$\omega=\frac{2\pi\times 80.0}{60}=8.38\ rad/s$

Now, using equation of motion for rotational motion, we have:

$\omega=\omega_0+\alpha t\\\\\alpha\to angular\ acceleration$

Plug in the given values and solve for α. This gives,

$8.38=0+\alpha \times 3.50\\\\\alpha=\frac{8.38}{3.50}=2.39\ rad/s^2$

Therefore, the angular acceleration is 2.39 rad/s².

Now, again using rotational equation of motion relating angular displacement, we have:

$\omega^2=\omega_0^2+2\alpha\theta\\\\\theta=\frac{\omega^2-\omega_0^2}{2\alpha }$

Plug in the given values and solve for 'θ'. This gives,

$\theta=\frac{(8.38)^2-0}{2\times 2.39}\\\\\theta=\frac{70.2244}{4.78}=14.69\ rad$

Convert radians to degrees using the conversion factor. This gives,

π radians = 180°

So, 1 radian =( 180 ÷ π ) degrees

Therefore, $14.69\ rad=14.69\times (\frac{180}{\pi})=841.68^\circ$

So, the number of degrees it rotates is 841.68 degrees.

3 0

3 years ago

Explain two ways you could reduce the friction between two surfaces

abruzzese [7]

A lubricant such as oil, grease, graphite powder can reduce the friction between two surfaces. Or using metal balls to space them and reduce the contact surface area as used in ball bearings.

3 0

3 years ago

An airplane is flying in a horizontal circle at a speed of 92.1 m/s. The 55.6 kg pilot does not want his radial acceleration to

Fudgin [204]

Answer:

r = 102.43 m

Explanation:

Newton's second law for this case is

F = ma

Where the acceleration is centripetal

a = v² / r

r = v² / a

They indicate that the radial acceleration is 8.45 g

r = v² / 8.45 g.

r = 92.1² / 8.45 9.8

r = 102.43 m

7 0

3 years ago

Explain how waves, energy, and matter are related

Stels [109]

Answer:

Mechanical waves need matter to transfer energy while electromagnetic waves do not. ... Waves change direction when they move from one material into another (matter) through the process of refraction. The wave will change direction when the speed of the wave changes.

3 0

3 years ago

. Write the following in the scientific notation of 0.0000002400m

aleksandr82 [10.1K]

Explanation:

<h2>Steps :</h2>

Move decimal from left to right =0 000000240.0
Then count the numbers before decimal and write it like this =240.0x10 power-9
That's all

hope it help

7 0

2 years ago