Pls help! If you know the answer

Answer:

Positive

Explanation:

In an endothermic reaction, the products are at a higher energy than the reactants. This means that the enthalpy change of the reaction (∆H) is positive

Answer:

1. direction of propagation of sound

2.medium through which sound trsnsmitted

Answer:

proton and neutron respectively.

Explanation:

Atoms of the same element will always have the same number of proton but will have different numbers of neutron if their mass numbers are different.

Answer:

1) The density of the object = 2500 kg/m³

2) The density of the oil = 1250 kg/m³

Explanation:

1) The information relating to the question are;

The mass of the object in air = 0.250 kgf

The mass of the object in water = 0.150 kgf

The mass of the object in the oil  = 0.125 kgf

By Archimedes's principle, we have;

The upthrust on the object in water = Mass in air - mass in water = The weight of the water displaced

The upthrust on the object in water = 0.250 - 0.150 = 0.1 kgf

∴ The weight of the water displaced = 0.1 kgf

Given that the object is completely immersed in the water, we have;

The volume of the water displaced = The volume of the object

The volume of 0.1 kg of water water displaced = Mass of the water/(Density of water)

The volume of 0.1 kg of water = 0.1/1000 = 0.0001 m³

The density of the object = (Mass in air)/ volume = 0.250/0.0001 = 2500 kg/m³

The density of the object = 2500 kg/m³

2) Whereby the mass of the object in the oil = 0.125 kgf

The upthrust of the oil = The weight of the oil displaced

The upthrust of the oil on the object = Mass of the object in air - mass of the object in the oil

The upthrust of the oil on the object = 0.250 - 0.125 = 0.125 kgf

The weight of the oil displaced = The upthrust of the oil

Given that the volume of the oil displaced = The volume of the oil, we have;

The volume of the oil displaced = 0.0001 m³

The mass of the 0.0001 m³ = 0.125 kg

Therefore the density of the oil = 0.125/0.0001 = 1250 kg/m³.

The density of the oil = 1250 kg/m³.

Explanation:

current = velocity/resistance

I = V/R

15/4

current = 3.75A

hope this helps...

Answer:

First, as you may know, the light travels at a given velocity.

In vaccum, this velocity is c = 3x10^8 m/s.

And we know that:

distance = velocity*time

Now, if some object (like a star ) is really far away, the light that comes from that star may take years to reach the Earth.

This means that the images that the astronomers see today, actually happened years and years ago (So the night sky is like a picture of the "past" of the universe)

Also, for example, if an astronomer sees some particular thing, he can apply a model (a "simplification" of some phenomena that is used to simplify it an explain it) and with the model, the scientist can infer the information of the given thing some time before it was seen.

The astronomers could know what was happening inside galaxies way back then by the fact that;

they examine the spectra of galaxies (or the overall colors of galaxies) with the highest redshifts they can find

Astronomers Measure the wavelength of the light that is stretched, so the light is seen as 'shifted' towards the red part of the spectrum by using spectroscopy. This measure is also called redshift.

This invokes a ray of light through a triangular prism that splits the light into various components known as spectrum.

The way the astronomers could use this concept to know what was happening in the galaxies before is by examining the spectra of galaxies that have the highest redshifts.

Read more at; https://brainly.com/question/15995216

Answer:

The volume of the cavity is 0.013m^3

Explanation:

To find the volume of the cavity, the major parameter missing is the diameter of the cavity itself. we can obtain this using the following steps:

Step one:

Obtain the volume of the cylinder by dividing the mass of the cylinder by the density.

Volume of the cylinder = 2.1 / 11.053 =0.19[tex]m^{3}[/tex]

Step two:

From the volume of the cylinder, we can get the radius of the cylinder.

[tex]radius = \sqrt{\frac{V}{\pi \times h}} = \sqrt{\frac{0.19}{\pi \times 0.32}} =0.44m[/tex]

Step three:

From the cross-sectional area, we can obtain the radius of the cavity.

Let the radius of the cavity be = r, while the radius of the cylinder be = R

CSA of cavity =

[tex]\pi({R^2}-r^2) = CSA\\0.65 = \pi (0.32^2-r^2)\\r= 0.115m[/tex]

Step Four:

calculate the volume of the cavity using volume =[tex]\pi r^2 \times h[/tex]

Recall that the cavity has the same height as the original cylinder

[tex]volume = \pi \times 0.115^2\times 0.32= 0.013m^3[/tex]

Explanation:

Volume is the amount of space an object takes up, while mass is the amount of matter in an object. ... To find the volume of an irregular sized object, one would use the displacement method for measuring volume and place the object in water and measure the amount of water that is displaced.

Answer:

To measure the volume of an irregularly shaped object, pour some water in a measuring cylinder. Then suspend the irregularly shaped object with a thread. After that , move the object gradually downwards and immerse it in water. The volume of the irregularly shaped object is the difference between the volume of the liquid before and after. After measuring the difference, we come to know about the volume of the irregularly shaped object.

Answer:

40085 Hz

Explanation:

We are given; Sound frequency emmision of bat;f = 38.9 kHz = 38900 Hz

Bat is moving at 0.015 times the speed of sound in air.

Speed of sound in air = 343 m/s

The formula for waves reflected off the wall is calculated from Doppler equation as:

f' = f(v + v_d)/(v - v_s)

Where;

f is the frequency = 38900 Hz

f' is the detected frequency,

v_d is the velocity of the detector = 0.015 × 343 = 5.145

v_s is the velocity of the source = 0.015 × 343 = 5.145 m/s

v is the velocity of the sound = 343 m/s

Thus;

f' = 38900(343 + 5.145)/(343 - 5.145)

f' ≈ 40085 Hz

Answer:

47.17 m

Explanation:

From the diagram of the question attached, The length of the legs are 25 m and 40 m . This legs form a right angle triangle with the length of the swimming course (L).

Pythagoras theorem states that for a right angle triangle with hypotenuse a and legs b and c, then:

a² = b² + c²

In the triangle, the length of the swimming course (L) is the hypotenuse and the two legs are 25 m and 40 m. Using Pythagoras:

L² = 25² + 40²

L² = 625 + 1600

L² = 2225

L = √2225

L = 47.17 m

Answer:

Explanation:

a) From the diagram, the load will be expressed in newton. The load will be the weight of the box on the inclined plane.

Load = mass * acceleration due to gravity.

Given the mass of the object = 100kg

acceleration due to gravity = 9.8m/s²

Load (in Newton) = 100*9.8

Load (in Newton) = 980N

b) The formula for calculating the velocity ratio of an inclined plane is expressed as VR = 1/sinθ where θ is the angle of inclination.

Given θ = 30°,

VR = 1/sin30°

VR = 1/0.5

VR = 1/(1/2)

VR = 1* 2/1

VR = 2

The velocity ratio is 2.

c) Length of the inclined plane can be calculated using the SOH, CAH, TOA trigonometry identity.

According to SOH, sinθ = opposite/hypotenuse

sin30°  = 1/2 = opp/hyp

This shows that the opposite side of the triangle is 1 and the hypotenuse is 2. The length if the inclined is the length of the longest side i.e the hypotenuse. Hence the length of the inclined plane is 2m

d) Mechanical Advantage is the ratio of the load to the effort applied on an object.

Given the Load = 980N and the effort applied to the load on the incline plane = 400N

MA = Load/Effort

MA = 980/400

MA = 2.45

e) Efficiency = MA/VR * 100

Efficiency = 2.45/2 * 100

Efficiency  = 122.5%

Answer:

kinetic and potential

Answer:

Answer: 19 meters.

Explanation:

We want to find the total displacement between t = 2s and t = 4s.

To do it, we can integrate our function, first write our velocity equation.

for t ≤ 3s, we have a linear equation, let's write it:

A linear relationship can be written as:

y = a*t + b

where a is the slope and b is the y-axis intercept.

For a line that passes through the points (x1, y1) and (x2, y2), the slope can be written as:

a = (y2 - y1)/(x2 - x1).

Now we can see that our line passes through the points (1, 0) and (0, -2)

then the slope is:

a = (0 -(-2)/(1 - 0) = 2/1 = 2

and knowing that when t = 0s, v(0s) = -2m/s, then our equation is:

v(t) = (2m/s^2)*t - 2m/s for t ≤ 3s

now, for t ≥3s the equation is constant, v(t) = 4m/s.

then we have

v(t) = (2m/s^2)*t - 2m/s -------if t ≤ 3s

v(t) = 4m/s ----- if t ≥ 3s

Now we integrate over time to get the position:

for t ≤ 3s we have:

p(t) = (1/2)*(2m/s^2)*t^2 - 2m/s*t + C

where C is a constant of integration, as we are calculating the displacement  this constant actually does not matter, so we can use C = 0m

p(t) = (1m/s^2)*t^2 - 2m/s*t  for t ≤ 3s

and p(3s) =  (1m/s^2)*3s^2 - 2m/s*3s = 9m - 6m = 3m is the initial position of the other part of the function.

for t ≥ 3s we have:

p(t) = 4m/s*t + p(3s) = 4m/s*t + 3m

then the position equation is:

p(t) = (1m/s^2)*t^2 - 2m/s*t  ---- t ≤ 3s

p(t) = 4m/s*t + 3m --- if t ≥ 3s

Now the displacement will be:

p(4s) - p(2s) where for each time, you need to use the correct function:

p(4s) = 4m/s*4s + 3m = 16m + 3m = 19m

p(2s) =  (1m/s^2)*2s^2 - 2m/s*2s = 4m - 4m = 0m

p(4s) - p(2s) = 19m - 0m = 19m

The butterfly displacement x from t=2 to 4s is 19 meters.

The spacing between two specified points is represented by the one-dimensional quantity of displacement (symbolised as d or s), commonly known as length or distance.

The total displacement between t = 2s and t = 4s.

Integrate our function, the velocity equation.

for t ≤ 3s, we have a linear equation, let's write it:

A linear relationship can be written as:

y = a x t + b

where a is the slope and b is the y-axis intercept.

For a line that passes through the points (x1, y1) and (x2, y2), the slope can be written as:

a = (y2 - y1)/(x2 - x1).

The line passes through the points (1, 0) and (0, -2)

The slope is:

a = (0 -(-2)/(1 - 0) = 2/1 = 2

When t = 0s, v(0s) = -2m/s, then our equation is:

v(t) = (2m/s²) x t - 2m/s for t ≤ 3s

now, for t ≥3s the equation is constant, v(t) = 4m/s.

v(t) = (2m/s²) x t - 2m/s -------if t ≤ 3s

v(t) = 4m/s ----- if t ≥ 3s

Now we integrate over time to get the position:

for t ≤ 3s we have:

p(t) = (1/2) x (2m/s²) x t^2 - 2m/s x t + C

where C is a constant of integration, to calculate the displacement  this constant actually does not matter,

p(t) = (1m/s²)*t^2 - 2m/s x t  for t ≤ 3s

and p(3s) =  (1m/s^2) x 3s² - 2m/s x 3s = 9m - 6m = 3m is the initial position of the other part of the function.

for t ≥ 3s we have:

p(t) = 4m/s x t + p(3s) = 4m/s x t + 3m

then the position equation is:

p(t) = (1m/s^2) x t² - 2m/s x t  ---- t ≤ 3s

p(t) = 4m/s x t + 3m --- if t ≥ 3s

Now the displacement will be:

p(4s) - p(2s) where for each time, you need to use the correct function:

p(4s) = 4m/s x 4s + 3m = 16m + 3m = 19m

p(2s) =  (1m/s²) x 2s²- 2m/s x 2s = 4m - 4m = 0m

p(4s) - p(2s) = 19m - 0m = 19m

Thus, the displacement is 19 m.

To learn more about displacement, refer to the link:
https://brainly.com/question/11934397

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Answer:

Well if they playing a game like that

Answer:

Given that;

Number of turns in the solenoid N = 310

Length of the solenoid L = 18 cm = 0.18 m

Radius of the solenoid r = 1.60 cm = 0.016 m

Current in the first Circuit I₁ = 1.90A

Number of turns in second coil N₂ = 4

Final Current solenoid I₂ = 5.0 A

Time interval to change the time Δt = 0.9 s

a)

According to Ampere's law, magnetic field inside a conductor is calculated as;

B₁ = ц₀N₁I₁ / L

(ц₀ = 4π × 10⁻⁷  constant)

therefore we substitute

{(4π × 10⁻⁷) ×  310 × 1.9A} / 0.18m

= 0.0041 T

b)

Magnetic field inside the solenoid after t = 0.9

B₁ = ц₀N₁I₂ / L

= {(4π × 10⁻⁷) ×  310 × 5.0A} / 0.18m

= 0.0108 T

c)

Area of coil is

A = πr²

A = π ×  ( 0.016 )²

A = 0.000804 m²

d)

Change in magnetic influx is

dФ = (B₂ - B₁) A

= ( 0.0108 T - 0.0041 T) × 0.000804 m²

= 0.0000053868 ≈ 5.39 × 10⁻⁶

e)

Average induced emf is

e = -N₂ ( dФ / dt )

e = ( -4 ) ( 5.39 × 10⁻⁶ / 0.9)

e = - 2.39 × 10⁻⁵V ( NOTE, this is not equal to the instantaneous induced emf )

f)

The induced emf is very low, so the contributions to the magnetic field in the coil is Negative.

Answer:

3504 m/s

Explanation:

Let x be the horizontal component of distance

y - vertical component of distance

t-time

ax- horizontal component of acceleration

ay-Vertical component of acceleration

Vx-horizontal component of velocity

Vy-Vertical component of velocity

horizontally: x = V_x ×t + ½×a_x×t²  

plugging the values we get

23500× cos 55º = 1350×cos25.0º × 10.20 + ½×a_x× (10.20)²  

⇒ax = 19.2 m/s²  

Moreover,

V'x = V_x + a_x×t = 1350×cos25.0º + 19.2×10.20= 1419 m/s  

similarly in vertical direction:

y = V_y×t + ½×a_y×t²  

23500×sin55º = 1350×sin25.0º×10.20s + ½×a_y×(10.20)²  

⇒a_y = 258 m/s²  

Also,

V'y = V_y + a_y×t = 1350×sin25.0º + 258×10.20 = 3204 m/s  

Therefore

V = √(V'x² + V'y²) = 3504 m/s  

therefore,  magnitude of final velocity of missile=3504 m/s

THANKS  

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Brainliest

Answer:

a = 0.5 m/s²

Explanation:

the type of problem is called a Newtons second law of motion.

and the equation would be the sum of F = m * a  where m = mass and a = acceleration

forces are 125N and the opposite direction is 120N

Eli pushes the table with a force of 120N towards Andy

and

Andy pushes the table with a force of 125N towards Eli

mass of table given as 10 kg.

using the equation

120N - 125N = 10kg * a

a = (120-125) / 10

a = -0.5 m/s² so the acceleration is in the direction of Andy's force towards Eli.

therefore a = 0.5 m/s²

Answer:

B.  

0.50 meters/second2

Explanation:

Answer:

The answer  is The acceleration is double its original value.

Explanation:

Hope this helps....

Have a nice day!!!!

Answer:

The acceleration is half of its original value

Explanation:

Answer:

The first answer is W and Z, since they appear to be a period apart. Dont know the second question. I did what I could, hope someone can answer the second.

Answer:

The correct option is energy levels

Explanation:

Rutherford's model of an atom suggests that an atom has a tiny positively charged central mass (now called the nucleus) which is surrounded by electrons (negatively charged) in a cloud-like manner.

Bohr's model went a bit further than the Rutherford's model in describing an atom by suggesting that the electrons which surrounds in the nucleus travel in fixed circular orbits. This description by Bohr was able to describe the energy levels of orbitals which assumes that smallest orbitals have the lowest energy while the largest orbitals have the highest energy.

Answer:

energy levels

hope this helped!

Explanation:

Answer:

Dx/dt  = 4,8 f/s

Explanation:

The ladder placed against a wall, and the ground formed a right triangle

with x and h the legs and L the hypothenuse

Then

L² = x² + h²          (1)

L = 26 f

Taking differentials on both sides of the equation we get

0  = 2x Dx/dt  + 2h Dh/dt    (1)

In this equation

x = 10   distance between the bottom of the ladder and the when we need to find, the rate of the ladder moving away from the wall

Dx/dt is the rate we are looking for

h = ?    The height of the ladder when  x = 10

As    L²  =  x²  + h²

h²  =  L²  -  x²

h²  =  (26)²  - (10)²

h²  =  676  -  100

h²  = 576

h = 24 f

Then equation (1)

0  = 2x Dx/dt  + 2h Dh/dt

2xDx/dt  = -  2h Dh/dt

10 Dx/dt  = - 24 ( -2 )      ( Note the movement of the ladder is downwards)

Dx/dt  =  48/10

Dx/dt  = 4,8 f/s

Answer:

Water waves are an example of waves that involve a combination of both longitudinal and transverse motions. As a wave travels through the waver, the particles travel in clockwise circles. The radius of the circles decreases as the depth into the water increases.

Answer:

13.4 m/s

Explanation:

Given:

Δx = 20 m

v₀ = 10 m/s

a = 2 m/s²

Find: v

v² = v₀² + 2aΔx

v² = (10 m/s)² + 2 (2 m/s²) (20 m)

v = 13.4 m/s

Answer:

H = 0.06 kWh

Explanation:

Given that,

Power of an electric lamp, P = 60 W

Voltage, V = 240 V

It is operated for 1 hour

We need to find the heat generated by the lamp. Heat generated is given by :

[tex]H=P\times t\\\\H=60\ W\times 1\ h\\\\H=60\ Wh\\\\H=0.06\ kWh[/tex]

So, 0.06 kWh of the heat is generated by the lamp.

Answer:

4.0

Explanation:

The following data were obtained from the question:

Force (F) = 20 N

Mass (m) = 5 kg

Acceleration (a) =.?

Force is simply defined as the product of mass and acceleration. Mathematically, it is expressed as

Force (F) = mass (m) x acceleration (a)

F = ma

With the above formula, we can obtain th acceleration of the body as follow:

Force (F) = 20 N

Mass (m) = 5 kg

Acceleration (a) =.?

F = ma

20 = 5 x a

Divide both side by 5

a = 20/5

a = 4 m/s²

Therefore, the value that will complete the last cell in the question above is 4.

Answer:

27.34 (no unit)

Explanation:

26.975*82.33%+29.018*17.67%

=27.34

Answer:

I assume its c. Since its talking about testing.

Explanation:

Answer:

The answer is test of durability

Explanation:

Answer:

[tex]\Large \boxed{\mathrm{5.67 \ seconds }}[/tex]

Explanation:

[tex]\displaystyle \mathrm{acceleration \ = \ \frac{final \ velocity - initial \ velocity }{elapsed \ time}}[/tex]

[tex]\displaystyle A \ = \ \frac{V_f - V_i }{t}[/tex]

[tex]\displaystyle 3 \ = \ \frac{25 - 8 }{t}[/tex]

[tex]\displaystyle 3 \ = \ \frac{17 }{t}[/tex]

[tex]\displaystyle t \ = \ \frac{17 }{3} \approx 5.67[/tex]