Intr- un vas de forma cubica cu latura de 0, 4m se afla un volume de 2 l de apa

A hollow spherical planet is inhabited by people who live inside it, where the gravitational is zero. When a very massive space

Ulleksa [173]

Answer:

c) nonzero, directed toward the spaceship

Explanation:

As we know that net gravitational force due to spherical shell inside all its points will always be zero

So if planet is a spherical shell then inside the planet net gravitational force is zero on the people living in it

So when massive spaceship land on the surface of planet then the gravitational force of the spaceship is experienced by the people inside the shell

So here the gravitational force on the people is nonzero and it is towards the spaceship which landed on the surface of planet

5 0

3 years ago

A jet aircraft is traveling at 260 m/s in horizontal flight. The engine takes in air at a rate of 53.3 kg/s and burns fuel at a

IrinaVladis [17]

Answer:

The thrust of the jet engine is 4188.81 N.

Explanation:

Given that,

Speed = 260 m/s

Rate in air= 53.3 kg/s

Rate of fuel = 3.63 kg/s

Relative speed = 317 m/s

We need to calculate the rate of mass change in the rocket

Using formula of rate of mass

$\dfrac{dM}{dt}=\dfrac{dM_{a}}{dt}+\dfrac{dM_{f}}{dt}$

Put the value into the formula

$\dfrac{dM}{dt}=53.3+3.63$

$\dfrac{dM}{dt}=56.93\ kg/s$

We need to calculate the thrust of the jet engine

Using formula of thrust

$T=\dfrac{dM}{dt}u-\dfrac{dM_{a}}{dt}v$

Put the value into the formula

$T=56.93\times317-53.3\times260$

$T=4188.81\ N$

Hence, The thrust of the jet engine is 4188.81 N.

7 0

3 years ago

A certain dam generates 120 MJ of mechanical (hydroelectric) energy each minute. If the conversion from mechanical to electrical

Karolina [17]

Answer:

electric energy ( power ) = 300000 W

Explanation:

given data

mechanical (hydroelectric) energy = 120 MJ/min = 2000000 J/s

efficiency = 15 % = 0.15

solution

we know that Efficiency of electric engine is expression as

Efficiency = Mechanical energy ÷ electric energy ......................1

and here dam electrical power output is

put here value in equation 1

electric energy ( power ) = Efficiency × Mechanical energy ( power )

electric energy ( power ) = 0.15 × 2000000 J/s

electric energy ( power ) = 300000 W

8 0

3 years ago

Which of the following is NOT an illuminated object?

Korolek [52]

Answer:

The answer here would be light bulb.

Explanation:

An Illuminated object is simply something that reflects light. And everything in the list is illuminated except the light bulb. Humans reflect light in the same way as desks and sidewalks. If we didn't we wouldn't technically be able to see other humans unless they were luminous. This brings me to the nest point. A light bulb is a luminous object because <em>it creates light on its own. </em>

A good example would be this:

The Sun is a luminous object

The Moon is a illuminated object

I hope this helped and didn't confuse you more, I kind of went all over the place with the explanation. Either way, if you need more help feel free to let me know! :)

-Matt

5 0

3 years ago

A wrench 0.500 m long is applied to a nut with a force of 80.0 N. Because of the cramped space, the force must be exerted upward

riadik2000 [5.3K]

Answer:

Torque, $\tau=34.6\ N.m$

Explanation:

It is given that,

Length of the wrench, l = 0.5 m

Force acting on the wrench, F = 80 N

The force is acting upward at an angle of 60.0° with respect to a line from the bolt through the end of the wrench. We need to find the torque is applied to the nut. We know that torque acting on an object is equal to the cross product of force and distance. It is given by :

$\tau=Fr\ sin\theta$

$\tau=80\times 0.5\ sin(60)$

$\tau=34.6\ N.m$

So, the torque is applied to the nut is 34.6 N.m. Hence, this is the required solution.

7 0

3 years ago