On the graph below, the line crosses the x axis on a velocity versus time

Why are most substances denser in the solid state than in the liquid state?

Rom4ik [11]

Answer:

For other liquids, solidification when the temperature drops includes the lowering of kinetic energy, which allows molecules to pack more tightly and makes the solid denser than its liquid form. Because ice is less dense than water, it is able to float at the surface of water.

Explanation:

have a great day:)

3 0

2 years ago

A satellite orbiting the moon very near the surface has a period of110 min. What is free-fall acceleration on the surface of the

Norma-Jean [14]

Answer:

1.54 m/s²

Explanation:

The free-fall acceleration is calculated as

g = w²r

Where w is the angular velocity of the satellite and r is the radius of the moon.

The angular velocity can be calculated as

$w=\frac{2\pi}{T}$

Where T is the period, so

T = 110 min = 110 x 60 s = 6600 s

Then,

$w=\frac{2\pi}{6600\text{ s}}=9.52\times10^{-4}\text{ rad/s}$

Finally, the radius of the moon is r = 1.7 x 10⁶ m, so the free-fall acceleration is

$\begin{gathered} g=w^2r \\ g=(9.52\times10^{-4})^2(1.7\times10^6) \\ g=1.54\text{ m/s}^2 \end{gathered}$

Therefore, the answer is 1.54 m/s²

5 0

1 year ago

Ultraviolet rays can cause skin cancer in humans and other living things. Explain why the depletion of the ozone layer by pollut

Charra [1.4K]

Teh humans are more revealed to the sun and that causes cancer because of all the uv rays and the ozone is the only thing thats helping us from uv rays

6 0

3 years ago

Read 2 more answers

If gas in a sealed container has a pressure of 50 kPa at 300 K, what will the pressure be if the temperature rises to 360 K?

Tresset [83]

Since gas is sealed in container, volume of gas will ramain constant. from ideal gas equation PV=nRT, P/T = nR/V ==> P/T = constant.( constant since v is constant so whole term must be constant). therefore, (P/T)1 = (P/T)2.==> 50/300 = P2/360. ==> P2= 50X360/300 = 60KPa. Hope this helps

8 0

3 years ago

A fully loaded Saturn V rocket has a mass of 2.92 x 106 kg. Its engines have a thrust of 3.34 x 107 N.

balandron [24]

Complete Question:

A fully loaded Saturn V rocket has a mass of 2.92 x 106 kg. Its engines have a thrust of 3.34 x 107 N. (8 marks)

a) What is the downward force of gravity on the rocket at blast-off?

b) What is the unbalanced force on the rocket at blast-off?

c) What is the acceleration of the rocket as it leaves the launching pad?

d) As the rocket travels upwards, the engine thrust remains constant, but the mass of the rocket decreases. Why?

e) Does the acceleration of the rocket increase, decrease, or remain the same as the engines continue to fire?

Answer:

a) $-2.8616 \times 10^{7} N$ is the downward force of gravity on the rocket at blast-off.

b) $4.784 \times 10^{6} N$ is the unbalanced force on the rocket at blast-off

c) $1.638 \mathrm{m} / \mathrm{s}^{2}$ is the acceleration of the rocket as it leaves the launching pad

d) Because the propellant here is burned up, hence the mass of the rocket seems to be varied (total mass of all its parts). Thereby, the mass decreases when the rocket moves upward.

e) The acceleration of the rocket increases when engines continue to fire

Explanation:

Given:

Mass (m) = $2.92 \times 10^{6} \mathrm{kg}$

a) In physics, weight can be defined as the applied force on a body by gravity. It is the product of mass (m) and gravity $\left(g=9.8 \mathrm{m} / \mathrm{s}^{2}\right)$

$\text { weight }(W)=m \times g=2.92 \times 10^{6} \times(-9.8)=28.616 \times 10^{6}=-2.8616 \times 10^{7} N$

The negative sign indicates the downward force of gravity.

b) To find the unbalanced force on the rocket at blast-off,

Accelerating force,

$F_{a}=F+W=3.34 \times 10^{7}+\left(-2.8616 \times 10^{7}\right)=(3.34-2.8616) \times 10^{7}$

$F_{a}=0.4784 \times 10^{7}=4.784 \times 10^{6} N$

c) Newton’s second law of motion states that the object’s acceleration depends on two variable:

Directly proportionate to the object’s force existed
Inversely proportionate to the mass of the objects

The equation can be given as below,

$Force =m \times acceleration$

$\text { Acceleration }=\frac{F_{a}}{m}=\frac{4.784 \times 10^{6}}{2.92 \times 10^{6}}=1.638 \mathrm{m} / \mathrm{s}^{2}$

d) The pushing of rocket upward will happen as long as the engine gets fired. The propellant here is burned up, hence the mass of the rocket seems to be varied (total mass of all its parts). Thereby, the mass decreases (taotal mass) when the rocket moves upward.

e) The acceleration of the rocket increases when engines continue to fire

Let consider $F_{a}$ is constant, mass gets decreasing, then the acceleration would be increasing (as mass and acceleration are inversely proportionate to each other) .

8 0

3 years ago