If solid iron is dropped in liquid iron, it will most likely

If a spacecraft in earth orbit is pushed by a thruster what will happen?

grin007 [14]

For the orbital speed of a spacecraft we know that

$v = \sqrt{\frac{GM}{r}}$

here

M = mass of the planet around which satellite is revolving

r = orbital radius

Now when thruster is used by the spacecraft its speed will change due to which orbital speed will change.

Since here while changing the speed mass of the planet will be same

we can say the speed of the spacecraft will changed by thruster due to which its orbital radius will change

so the correct answer must be

<em>b. the spacecraft will change motion and will maintain this new orbit until the thruster is fired again.</em>

8 0

3 years ago

. Two astronauts are 1.90 m apart in their spaceship. One speaks to the other. The conversation is transmitted to earth via elec

melomori [17]

Answer:

d= 1650 km.

Explanation:

Assuming that sound waves travel along a straight line at a constant speed of 346 m/s, we can find the time needed for the sound to travel the distance of 1.9 m between the astronauts, just applying the definition of average velocity, as follows:

$t = \frac{\Delta x}{v} =\frac{1.9m}{346m/s} = 5.5 msec (1)$

The electromagnetic waves travel in free space at the same speed of light in vacuum ( since light is a electromagnetic wave indeed), i.e., 3*10⁸ m/s.
Applying the same formula than in (1) we can solve for the distance d, as follows:

$d = v*t = 3e8 m/s*5.5e-3s = 1650 km (2)$

3 0

3 years ago

Fifty grams of water cooled from 50 'C to 10 'C. If the specific heat of water is 4.2 , how much heat was released ?

ryzh [129]

THe anwser woul have to be C

4 0

3 years ago

Which will displace a greater volume of water from a full tub, a 2 gram piece of iron or a floating toy boat that weighs 2 grams

Westkost [7]

2 gram piece of iron, because is doesn't float.

5 0

4 years ago

Although 0 dB is often referred to as the lower threshold of human hearing, it is important to realize that the human ear is not

IRISSAK [1]

Answer:

20 Hz

15.8 times

Explanation:

A

Although the range of frequency for any human's ear is usually said to be between 20 Hz and 20 kHz. And since the question asked for the least intense frequency, that has to be 20 Hz. Essentially the frequency most people perceive the least intense sound is 20 Hz.

B

A 100-Hz sound must be 10^1.2 times or 15.8 times more intense compared to a 1000-Hz sound to be perceived as equal to 60 phons of loudness

5 0

3 years ago