Ask question

Ask question

All categories

3 years ago

6

A 27 kg disk with a radius of 1.3m is spinning at an angular speed of 15 rad/s. What is the rotational kinetic energy of the dis

k?

1 answer:

satela [25.4K]3 years ago

4 0

Answer:

the rotational kinetic energy of the disk is 5,133.375 J

Explanation:

Given;

mass of the disk, m = 27 kg

radius of the disk, r = 1.3 m

angular speed, ω = 15 rad/s

The rotational kinetic energy of the disk is calculated as;

$K.E_{rot} = \frac{1}{2}I \omega^2\\\\ where;\\I \ is \ moment \ of \ inertia\\\\K.E_{rot} = \frac{1}{2} \times (mr^2) \times \omega ^2\\\\ K.E_{rot} = \frac{1}{2} \times (27\times 1.3^2) \times \ 15^2\\\\K.E_{rot} = 5,133.375 \ J$

Therefore, the rotational kinetic energy of the disk is 5,133.375 J

You might be interested in

The escape velocity at the surface of Earth is approximately 11 km/s. What is the mass, in units of ME (the mass of the Earth),

SVETLANKA909090 [29]

Answer:11 km/s

Explanation:

Given

Escape velocity at the surface of earth is 11 km/s

Escape velocity is given by

$V_e=\sqrt{\frac{2GM}{R}}$

Escape velocity at the surface of earth

$11=\sqrt{\frac{2GM}{R}}$ --------------------1

If Escape velocity is three times and the radius is also the three times

$V_e_2=\sqrt{\frac{2G(3M)}{3R}}$

$V_e_2=\sqrt{\frac{2GM}{R}}=V_e$

i.e. $V_e_2=11 km/s$

5 0

3 years ago

A hula hoop is rolling along the ground with a translational speed of 26 ft/s. It rolls up a hill that is 16 ft high. Determine

nikklg [1K]

Answer:12.8 ft/s

Explanation:

Given

Speed of hoop $v=26\ ft/s$

height of top $h=16\ ft$

Initial energy at bottom is

$E_b=\frac{1}{2}mv^2+\frac{1}{2}I\omega ^2$

Where m=mass of hoop

I=moment of inertia of hoop

$\omega$ =angular velocity

for pure rolling $v=\omega R$

$I=mR^2$

$E_b=\frac{1}{2}mv^2+\frac{1}{2}mR^2\times (\frac{v}{R})^2$

$E_b=mv^2=m(26)^2=676m$

Energy required to reach at top

$E_T=mgh=m\times 32.2\times 16$

$E_T=512.2m$

Thus 512.2 m is converted energy is spent to raise the potential energy of hoop and remaining is in the form of kinetic and rotational energy

$\Delta E=676m-512.2m=163.8m$

Therefore

$163.8 m=mv^2$

$v=\sqrt{163.8}$

$v=12.798\approx 12.8\ ft/s$

7 0

3 years ago

5. What is an excess of electric charge on an<br> object?

ValentinkaMS [17]

Answer:

Explanation:. What is an excess of electric charge on an

object?

8 0

3 years ago

Would you rather be beautiful but you cant look at yourself or be ugly and no one else can see you

WARRIOR [948]

Whats the point of being either of them?

If your Beautiful, you cant look at yourself...

And if your ugly, no one else can see you...

I'd rather not exist LOL XD

6 0

4 years ago

A constant force of 5KN pulls a crate along a distance of 15 m in 75s.What is the power

xxMikexx [17]

Explanation:

We know,

1KN = 1000N

Then, Force(F) = 5*1000N

=5000N

Here,

Power (P)=Work(W)/Time(T)

=Force * distance/ Time (W = F*s)

= 5000*15/75

=1000

So, The power of body or object is 1000Watt.

I hope this will be helpful for you.

8 0

4 years ago