Name the principal on which a rocket works

When an ice cube in a glass of water melts, the water level _____. A. remains the same B. rises C. falls

A. The water level Remains the same

6 0

3 years ago

What is the percentage of the incoming solar radiation from the top of the atmosphere the gets reflected right back out into spa

san4es73 [151]

Answer: We can define the solar constant as a measure of the luminous flux density.

Explanation:

The solar constant or solar constant is the amount of energy radiated at the upper limit of the Earth's atmosphere per unit time perpendicular to the unit surface, at the Earth's mean distance from the sun. Amounts to 1367.7 W / m² ± 6 W / m². The sun's constant includes all kinds of electromagnetic radiation, not just visible light. The average value is 1,368 kW / m2 and changes slightly with solar cycles. The amount of these constant changes over one year and has different benefits.

4 0

3 years ago

What is: the fastest car the fastest animal the fastest human the fastest aeroplane

seropon [69]

The Hennessey Venom GT is the fastest road car in the world.
The fastest land animal is the Cheetah
Usain Bolt, the World's fastest man.
The Lockheed SR-71 "Blackbird" the fastest airplane.

4 0

3 years ago

Read 2 more answers

An 85,000 kg stunt plane performs a loop-the-loop, flying in a 260-m-diameter vertical circle. at the point where the plane is f

konstantin123 [22]

A) When the plane is flying straight down, there are three forces acting on it:
- the centripetal force $F=m \frac{v^2}{r}$ , directed toward the center of the circle (so, horizontally)
- the weight of the plane: $W=mg$ , downward, so vertically
- a third force, given by the propulsion of the plane, which is accelerating it towards the ground (because the problem says that the plane has an acceleration of a=12 m/s^2 towards the ground)

The radius of the circle is $r= \frac{260 m}{2} = 130 m$ , so the centripetal force acting on the plane is
$F_c=m \frac{v^2}{r} = \frac{(85000 kg)(55 m/s)^2}{130 m}=1.98 \cdot 10^6 N$
On the vertical axis, we have two forces: the weight
$W=mg=(85000 kg)(9.81 m/s^2)=8.34 \cdot 10^5 N$
and the other force F given by the propulsion. Since we know that their sum should generate an acceleration equal to $a=12 m/s^2$ , we can find the magnitude of this other force F by using Newton's second law:
$F+mg=ma$
$F=m(a-g)=(85000kg)(12 m/s^2-9.81 m/s^2)=1.86 \cdot 10^5 N$

So, the net force acting on the plane will be the resultant of the centripetal force (acting in the horizontal direction) and the two forces W and F (acting in the vertical direction):
$R= \sqrt{(F_c^2+(W+F)^2}=$
$= \sqrt{(1.98\cdot 10^6N)^2+(8.34 \cdot 10^5N+1.86 \cdot 10^5 N)^2} =2.23 \cdot 10^6 N$

(b) The tangent of the angle with respect to the horizontal is the ratio between the sum of the forces in the vertical direction (taken with negative sign, since they are directed downward) and the forces acting in the horizontal direction, so:
$\tan \theta = \frac{-(W+F)}{F_c}= -0.5$
And so, the angle is
$\theta = \arctan (-0.5)=-26.8 ^{\circ}$

7 0

3 years ago

Which of the following is a major way in which oceans contribute to weather systems?

mylen [45]

Since, the options are not given the question is incomplete the complete question is as follows.:

Which of the following is a major way in which oceans contribute to weather systems?

provide a diverse habitat for many organisms

experience changes in amounts of dissolved salts

store and transport the Sun's heat energy

reach depths that can be as much as 12000 meters

Answer: Store and transport the Sun's heat energy.

Explanation:

Oceanic currents are just like a conveyor belt. It helps in transportation of the warm water and the precipitation from the equator to the poles and the cold water in the poles towards the tropics. This way the oceans counteract the uneven distribution of the radiation of sun that reaches upto the surface earth. This will regulate the global climate.

4 0

3 years ago