Properties of helium

Answers

Answer 1

Answer:

Helium has many unique properties: low boiling point, low density, low solubility, high thermal conductivity and inertness, so it is use for any application which can explioit these properties. Helium was the first gas used for filling balloons and dirigibles


Related Questions

Two cars start moving from the same point on a rectilinear path at the same time, heading to the same destination 90 km away. The first travels at an average speed of 50 km/h and the second at 60 km/h. Deter- mine the time interval separating the arrival of the two cars to their destination.

Answers

Answer:

0.3 hour

Explanation:

From the question given above, the following data were obtained:

Distance travelled = 90 km

Speed of 1st car = 50 km/h

Speed of 2nd car = 60 km/h

Time interval separating the two cars =?

Next, we shall determine the time taken for each car to get to the destination. This can be obtained as follow:

For the 1st car:

Distance travelled (d) = 90 km

Speed of 1st car (S₁) = 50 km/h

Time (t₁) =?

Speed = Distance /time

S₁ = d/t₁

50 = 90 / t₁

Cross multiply

50 × t₁ = 90

Divide both side by 50

t₁ = 90 / 50

t₁ = 1.8 hours

For the 2nd car:

Distance travelled (d) = 90 km

Speed of 2nd car (S₂) = 60 km/h

Time (t₂) =?

Speed = Distance /time

S₂ = d/t₂

60 = 90 / t₂

Cross multiply

60 × t₂ = 90

Divide both side by 60

t₂ = 90 / 60

t₂ = 1.5 hours

Finally, we shall determine the time interval separating the arrival of the two cars. This can be obtained as follow:

Time for the 1st car (t₁) = 1.8 hours

Time for the 2nd (t₂) = 1.5 hours

Time interval separating the two cars (tₛ) =?

tₛ = t₁ – t₂

tₛ = 1.8 – 1.5

tₛ = 0.3 h

Thus, the interval separating the arrival of the two cars is 0.3 hour

Can someone please help me?
Please also explain how you got the net force, thank you.
The questions are in the picture i attached below.

Answers

Answer:

unbalanced 1st answer

right 2nd answer

Answer:

hi, your answers are correct

Explanation:

what is linear magnification​

Answers

Answer:

Linear magnification refers to the ratio of image length to object length measured in planes that are perpendicular to the optical axis. A negative value of linear magnification denotes an inverted image.

Explanation:

Answer:

i hope it help

Explanation:

stay happy and safe

A wave has a wavelength of 0.02m and period of 8.0*10^-2 seconds. calculate it's speed. (showing working)​

Answers

Answer:

[tex]v = 0.25m/s[/tex]

Explanation:

Given

[tex]\lambda = 0.02m[/tex] --- Wavelength

[tex]T = 8.0 * 10^{-2}s[/tex] --- Period

Required

Determine the velocity of the wave

This is calculated using:

[tex]v = \frac{\lambda}{T}[/tex]

[tex]v = \frac{0.02m}{8.0*10^{-2}s}[/tex]

[tex]v = \frac{0.02m}{8.0*0.01s}[/tex]

[tex]v = \frac{0.02m}{0.08s}[/tex]

[tex]v = 0.25m/s[/tex]

Hence, the velocity is 0.25m/s

Which is a benefit of strength training? O Decreased blood flow to muscles O Improved oxygen delivery Flexibility of tendons and joints O Increased lean muscle tissue ​

Answers

Answer:

Increased lean muscle tissue.

Explanation:

I hope this helps :) Tell me if I am wrong!

Answer:

Increased lean muscle tissue.

Explanation:

i took the test!

What is the distance from one peak to the next peak called?​

Answers

Answer:

wavelength

Explanation:

Electromagnetic waves is a propagating medium used in all communications device to transmit data (messages) from the device of the sender to the device of the receiver.

Generally, the most commonly used electromagnetic wave technology in telecommunications is radio waves.

Radio waves can be defined as an electromagnetic wave that has its frequency ranging from 30 GHz to 300 GHz and its wavelength between 1mm and 3000m. Therefore, radio waves are a series of repetitive valleys and peaks that are typically characterized of having the longest wavelength in the electromagnetic spectrum.

Basically, as a result of radio waves having long wavelengths, they are mainly used in long-distance communications such as the carriage and transmission of data.

The distance from one peak to the next peak is called wavelength. This distance is also equal to the distance from one trough of a wave to another.

Mathematically, wavelength is calculated using this formula;

[tex] Wavelength = \frac {speed}{frequency} [/tex]

Electromagnetic waves are
O
A. forms of matter.
O
B. forms of space.
O
C. longitudinal waves.
O
D. transverse waves.

Answers

the answer is d transverse waves
The answerrrrrrrrrr is D

what is meant by the resultant force acting on an object?

Answers

Answer:

The resultant force is the single force that would produce the same effect on an object as two or more forces that are applied to the object. To find the resultant force, first draw a free body diagram, which is a diagram that shows all the applied forces using arrows in the direction of each force.

Alyssa is taking a walk on a nature path near her neighborhood. She
carries a compass with her. As she walks along the path, she notices
the needle on the compass is occasionally deflected from its original
position. If she has not changed the direction she is walking, what is
most likely causing the occasional shift in the needle? (1 point)
O Changes in pressure
0 Changes in temperature
O Sources of electrical current
O Changes to Earth's magnetic field

Answers

Answer:

C. Sources of electrical current!

Hope this helps :)

Answer:

Sources of electrical current

Explanation:

Got it right on the test.

________ 8. The pH of a solution is a measure of the concentration of H+ ions in it. TRUE OR FALSE

Answers

Answer:

False.

Explanation:

Potential of Hydrogen is the full form of PH.

Potential of Hydrogen tells about the acidity or basicity of the solution.

The pH of a solution is a measure of the concentration of hydrogen ions [tex](H+)[/tex] ions and hydroxide ions [tex](OH-)[/tex] in a solution.

So, the given statement is false.

A car engine produces a force of 2000N while moving a distance of 200m in a time of 10s. What is the power developed by the engine ​

Answers

Power = work/time
Work = force * distance

(2000 N * 200 m) / 10 s = 40,000 Joules

Is this spring or winter?

Answers

The season is Spring

plz help will mark the brainliest​

Answers

Answer:

yesssssssssssssssssssssssssssssssssssss

No
MARK ME BRAINLEST

A body is at equilibrium under the action of three forces. One force is 10N acting due east and one is 5N in the direction 60° north east. What is the magnitude and direction of the third force?​

Answers

Answer:

If the body is in equilibrium the two forces add up and the third is the opposite of the resultant.

F(1x)=F(1)=10 N

F(2x)=F(2)cos60=5•0.5=2.5 N

F(2y) =F(2)sin60 = 5•0.866= 4.33 N

F(3x) =- F(x)=- (10+2.5 )= -12.5 N

F(3y) =- F(2y)= - 4.33 N

F(3) = sqrt{ F(3x)²+F(3y)²} =13.23 N

tan φ = F(3y)/F(3x) =4.33/12.5=0.364

φ = 19.1⁰ (south-west)

Explanation:

The initial speed of a dropped ball is 0 m/s after 2 seconds the ball travels at a speed of 20 m/s what is the acceleration of the ball ?

Answers

Answer:

Please find attached file

Explanation:

The rate of change of velocity with respect to time is known as acceleration. The acceleration of the ball will be 10m/s.

What is acceleration?

The rate of change of velocity with respect to time is known as acceleration. According to Newton's second law, the eventual effect of all forces applied to a body is its acceleration.

The pace at which a body's velocity varies is represented by acceleration, which is a vector quantity.

The given data in the problem is given by ;

u is the initial speed of ball = 0 m/sec

v is the final speed of the ball= 10 m/sec

t is the time interval= 2 second

a is the acceleration of ball=? m/sec²

The formula for acceleration is;

[tex]\rm a=\frac{(v-u)}{t} \\\\ \rm a=\frac{(20-0)}{2} \\\\\rm a=10\ m/sec^2[/tex]

Hence the acceleration of the ball will be 10m/s².

To learn more about the acceleration refer to the link;

https://brainly.com/question/2437624

a body is thrown at an angle 30°to the horizontal with kinetic energy 40J.atbthe highest point of its motion the kinetic energy will be?​

Answers

At it’s peak the vertical component will be 0. The horizontal component will remain: 40 * cos30 = 20 J

What is the intensity of the electric current in one coil, if the number of the coils is 10, length of the coil is 5m, and magnetic induction is 8T?

Answers

Answer:

I think the answer is D...

Explanation:

Kerry drops her iPhone accidently as she is standing on an overview. How fast is the iPhone moving after 3s?

Answers

Answer:

really fast? xP

Explanation:

Someone help me please I need to pass this quiz , this is the only quiz that It making me fail this class !!!

Select the correct items. Click the bottom right arrow to go to the next set . Click the checkmark ( Available on the last set ) to submit all your answers

Slow twitch muscle Fibers

Can contract repeatedly
Only anaerobic sources
Both aerobic & anaerobic
Produce most force
Endurance activities
Fast contraction speed
Fatigue quickly
Only aerobic sources
Speed, strength, power


Fast twitch Type lla muscle Fibers

Only aerobic sources
Fast contraction speed
Speed, strength, power
Only anaerobic sources
Fatigue quickly
Endurance activities
Produce most force
Can contract repeatedly
Both aerobic & anaerobic


Fast twitch type llx muscle Fibers

Can contract repeatedly
Only anaerobic sources
Only aerobic sources
Both aerobic & anaerobic
Fast contraction speed
Produce most force
Fatigue quickly
Endurance activities
Speed, strength, power

Answers

Answer:

1. Endurance activities

Only aerobic source

2. Can contract repeatedly

Speed strength and power.

Both aerobic and anaerobic sources

3. Fast contraction speed

Only anaerobic sources

Produce most force

Fatigue quickly

Speed, strength and power

Explanation:

I hope this helps. Although, I'm about 80% sure of the answer.

A 2750 kg helicopter flies horizontally at constant speed. Air resistance creates a 7510 n backward force. What is the magnitude of the lift force created by the propellers

Answers

Answer:

Explanation:

Let lift force F be created by propellers at angle of Ф with the horizontal .

The vertical component of this force will balance the weight of helicopter and horizontal component will balance the air resistance .

F sinФ = mg = 2750 x 9.8 = 26950 N

F cosФ = 7510 N

Squaring and adding ,

F² = 26950² + 7510²

= 726302500 + 56400100

= 782702600

F = 27976.82 N .

Which of the following is an example of an opposing force?
A.Gravity pulling a ball down a hill
B.Wind blowing a leaf off of a tree
C.Gravity holding a rock still on the ground
D.Water pushing against someone as they wade through a pool

Answers

Water pushing against someone as they wade through A pool

The principal ran a marathon, 26.2 miles in 3 hours. This is an example of.....
A-speed
B-velocity
C-acceleration

Answers

Speed = distance/ time
8.73 mph = 26.2/ 3

How many different atoms are there in a compound? ​

Answers

Answer:

2 or more atoms

Explanation:

yes yes yes yes yes yes yes yes

Answer:

Two or more

Explanation:

It's mostly two but unique structures might compose of more than 2

Transforme: a) 2 km em m b) 1,5 m em mm c) 5,8 km em cm d) 0,4 m em mm e) 27 mm em cm f) 126 mm em m g) 12 m em km

Answers

Answer:

a) 2000 m

b) 1500 mm

c) 580000 cm

d) 400 mm

e) 2.7 cm

f ) 0.126 m

g) 0.012 km

Explanation:

Transform

a) 2km to m

   1 km = 1000m

hence : 2 km = 2 * 1000 =  2000 m

b) 1.5m to  mm

    1 m = 1000 mm

hence: 1.5 m = 1.5 * 1000 = 1500 mm

C) 5.8 km  to cm

     1 km = 100000 cm

hence ;5.8 km = 5.8 * 100000 = 580000 cm

D) 0.4 m   to  mm

   1 m = 1000 mm

hence; 0.4 m =  0.4 * 1000 = 400 mm

E) 27 mm to  cm

   1 mm = 0.1 cm

hence ; 27 mm = 27 * 0.1  = 2.7 cm

F) 126mm  to m

    1 mm = 0.001 m

hence ;  126 mm = 126 * 0.001 = 0.126 m

G) 12m  to Km

   1 m = 0.001 km

hence ; 12 m = 12 * 0.001 = 0.012 km

How much work is performed when a 50 kg crate is pushed 15 m with a force of 20 N?

Answers

Answer:

300 jules

Explanation:

A plane taxies onto the runway, preparing for take off. It starts at rest before it's engines start. The plane's top speed, before it takes off the ground, is about 8820 km/s. If the take off takes about 32.8s, what is the acceleration of the plane?

Answers

Answer:

Explanation:

This is a fast plane! At it's takeoff speed, it could fly around the world in 5 seconds!

Acceleration is defined as the change in speed over the change in time.

[tex]a = \frac{v_f - v_o}{t}[/tex]

Where v_f is the final velocity, v_o is the original velocity, and t is the time.

We know v_f = 8820km/s.

v_o = 0 km/s. The plane "starts at rest before it's engine start." So we know it starts from zero velocity.

t = 32.8 seconds.

You can solve the equation from there.

______ images are obtained when the plane mirror are kept parallel to the each other​

Answers

.infinite.

&

also

.virtual.


Under constant acceleration, the average velocity of a particle is half the sum of its initial and final
velocities. Is this still true if the acceleration is not constant? Explain.

Answers

Answer:

It is not still true that the average velocity of the particle is equal to half the sum of the initial and final velocities when the acceleration of the particle is not constant

Explanation:

The motion of a particle under constant acceleration, 'a', is be given by the following kinematic equations;

v² = u² + 2·a·s

v = u + a·t

Where;

v = The final velocity of the particle

u = The initial velocity of the particle

a = The acceleration of the particle

s = The distance through which the particle travels

t = The time of motion of the particle

By simplifying the above equation, we have;

v² - u² = 2·a·s

(v² - u²)/(2·a) = s

(v - u) × (v + u)/(2 × a) = s

((v - u)/a) × ((v + u)/2) = s

From v = u + a·t, we have;

t = (v - u)/a

∴ ((v - u)/a) × ((v + u)/2) = t × ((v + u)/2) = s

∴ ((v + u)/2) = s/t

The average velocity = (Total distance traveled by the particle) ÷ (The time of travel of the particle)

∴ The average velocity = s/t = ((v + u)/2) = Half the sum of the initial and final velocity

However, it is not still true that the average velocity of the particle is equal to half the sum of the initial and final velocities when the acceleration of the particle, 'a', is not constant, as the velocity time graph is no longer a straight line graph and the distance traveled by the particle, 's', which is the area under the velocity time graph, 'A', (given by the sum of area of the triangle and the rectangle given by the area under straight line graph for constant velocity) cannot be given directly by the product of the time and the average velocity.

3. Bart ran 5000 meters from the cops and an average speed of 10 meters/second before he got
caught. How long did he run?

Answers

Answer:

8 minutes and 20 seconds

Explanation:

5000/10 to get the number of seconds, which is 500, then you convert 500 seconds to minutes and you get 8 minutes and 20 seconds

Please answer fast!!!
which of the following is an example of unbalanced force?
1. A chair leaning on a wall
2. A stroller being pushed
3. A ball on the grass
4. A book sitting on a table

Answers

Answer:1. A chair leaning on a wall

Explanation:

3 A ball on the grass
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