True or false air contains 78 percent hydrogen, 21 percent oxygen, and 0.03 percent carbon dioxide

Which statement explains what happens to older crust during seafloor spreading?

ikadub [295]

Answer:

the last one, It moves away from a mid-ocean ridge.

6 0

3 years ago

A moving roller coaster speeds up with constant acceleration for 2.3s until it reaches a velocity of 35m/s. During this time, th

nata0808 [166]

Hope this answer helps: option B

Explanation:

9 0

3 years ago

If light moves at a speed of 299,792,458 m/s, how long will it take light to move a distance of 1,000 km

astra-53 [7]

Answer:

change 1000km into Metre

1000km=1000000 M

speed= distance/time

time=distance/speed

time=1000000/299792458

time= 0.0033second

6 0

3 years ago

You are sitting on a merry-go-round of mass 200 kg and radius 2m that is at rest (not spinning). Your mass is 50 kg. Your friend

Bogdan [553]

Answer:

a. $\tau=200J$ b. $\alpha=0.44 \frac{rad}{s^2}$ c. $\alpha=0.33\frac{rad}{s^2}$ d. The angular acceleration when sitting in the middle is larger.

Explanation:

a. The magnitude of the torque is given by $\tau=rF\sin \theta$ , being r the radius, F the force aplied and $\theta$ the angle between the vector force and the vector radius. Since $\theta=90^{\circ}, \, \sin\theta=1$ and so $\tau=rF=2m100N=200Nm=200J$ .

b. Since the relation $\tau=I\alpha$ hols, being I the moment of inertia, the angular acceleration can be calculated by $\alpha=\frac{\tau}{I}$ . Since we have already calculated the torque, all left is calculate the moment of inertia. The moment of inertia of a solid disk rotating about an axis that passes through its center is $I=\frac{1}{2}Mr^2$ , being M the mass of the disk. If we assume that a person has a punctual mass, the moment of inertia of a person would be given by $I_p=m_pr_p^{2}$ , being $m_p$ the mass of the person and $r_p^{2}$ the distance from the person to the center. Given all of this, we have

$\alpha=\frac{\tau}{I}=\frac{\tau}{I_{disk}+I_{person}}=\frac{Fr}{\frac{1}{2}Mr^2+m_pr_p^{2}}=\frac{200Nm}{\frac{1}{2}200kg*4m^2+50kg*1m^2}=\frac{200\frac{kgm^2}{s^2}}{450Nm^2}\approx 0.44\frac{rad}{s^2}$ .

c. Similar equation to b, but changing $r_p=2m$ , so

$alpha=\dfrac{200\frac{kgm^2}{s^2}}{\frac{1}{2}200*4kg\,m^2+50*4 kg\,m^2}=\dfrac{200}{600}\dfrac{1}{s^2}\approx 0.33 \frac{rad}{s^2}$ .

d. The angular acceleration when sitting in the middle is larger because the moment of inertia of the person is smaller, meaning that the person has less inertia to rotate.

5 0

3 years ago

What form of music has two parts and has two contrasting melodies? *

aleksandr82 [10.1K]

Answer: Ternary

Explanation: Ternary Form also has two parts, but is different from Binary Form. Relevance. Ternary form, sometimes called song form, is a three-part musical form where the first section (A) is repeated after the second section (B) ends. different words and same music.

Please mark as brainliest!

5 0

2 years ago