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3 years ago

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Physics

1 answer:

marshall27 [118]3 years ago

4 0

Answer: The answer is A, B, D, and E

Explanation: Choose all those answers. USATestPrep says so.

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The elements from this section of the periodic table all belong to the same

Lady_Fox [76]

Answer:

The answer is:

B) period

3 0

3 years ago

Need help finding the average speed.

Snowcat [4.5K]

Explanation:

To find the average of these numbers, we just have to add the three numbers together and divide by 3.

2.07 + 0. 74 + 1.33 = 4.14. 4.14 / 3 = 1.38
1.09 + 1.40 + 0.31 = 2.8. 2.8 / 3 ≈ 9.3333333/ 9 1/3
0.95 + 1.61 + 0.56 = 3.12 / 3 = 1.04
0.81 + 1.89 + 1.08 = 3.78 / 3 = 1.26

5 0

4 years ago

A box has sides of 10 cm, 8.2 cm, and 3.5 cm. What is its volume?

Ksju [112]

The volume would be 287cm³. Multiply all the 3 numbers by each other

4 0

3 years ago

A large rocket has a mass of 2.00×10⁶ kg at takeoff, and its engines produce a thrust of 3.50×10⁷ N. Find its initial accelerati

Kazeer [188]

Answer:

17.5 m/s²

1.90476 seconds

Explanation:

t = Time taken

u = Initial velocity

v = Final velocity

s = Displacement

a = Acceleration

Force

$F=ma\\\Rightarrow a=\frac{F}{m}\\\Rightarrow a=\frac{3.5\times 10^7}{2\times 10^6}\\\Rightarrow a=17.5\ m/s^2$

Initial acceleration of the rocket is 17.5 m/s²

$v=u+at\\\Rightarrow \frac{120}{3.6}=0+17.5t\\\Rightarrow t=\frac{\frac{120}{3.6}}{17.5}=1.90476\ s$

Time taken by the rocket to reach 120 km/h is 1.90476 seconds

Change in the velocity of a rocket is given by the Tsiolkovsky rocket equation

$\Delta v=v_{e}\ln \frac{m_0}{m_f}$

where,

$m_0$ = Initial mass of rocket with fuel

$m_f$ = Final mass of rocket without fuel

$v_e$ = Exhaust gas velocity

Hence, the change in velocity increases as the mass decreases which changes the acceleration

4 0

3 years ago

A sound source emits 20.0 W of acoustical power spread equally in all directions. The threshold of hearing is 1.0 × 10-12 W/m2.

ahrayia [7]

Answer:

0.0018 W/m²

Explanation:

Power and intensity are related as:

$I=\frac{P}{4\pi r^2}$

P= 20.0 W (given)

r = 30.0 m (given)

$I=\frac{20.0}{4\pi(30.0)^2}=0.0018 W/m^2$

Intensity in decibels:

$I(dB)=10log\frac{I}{I_o}\\=10log\frac{0.0018}{10^{-12}}=92.5 dB$

7 0

3 years ago