What does the cross sign in the middle mean???

Answer:

the rock will sink. this is because it is more dense than water

Answer:it will sink

Explanation:

because the density of water is 1g and the rock is heavier the the density of water

Answer:

The final temperature is 31.94°

Explanation:

The mass of the water in the container m₁ = 200 g = 0.2 kg

The initial temperature of the water,  T₁₁ = 30°C

The mass of the iron, m₂ = 200 g = 0.2 kg

The temperature of the iron T₂₁= 50°C is immersed in the water,

The specific heat capacity of the water, c₁ = 4200 J/(kg·°C)

The specific heat capacity of the iron, c₂ = 450 J/(kg·°C)

Heat capacity relation is given by the formula;

Heat capacity Q = Mass, m × Specific heat capacity, c × Temperature change, (T₂ - T₁)

Given that energy can neither be created nor destroyed, and with the assumption that all the heat lost by the nail is gained by the water we have;

Heat lost by iron nail = Heat gained by the  water

m₁ × c₁ × (T₂ - T₁₁) = m₂ × c₂ × (T₂₁ - T₂)

Where, T₂ is the final temperature

0.2 kg × 4200 J/(kg·°C) × (T₂ - 30) = 0.2 kg × 450 J/(kg·°C) × (50° - T₂)

840·T₂ - 25200 = 4500 - 90·T₂

4500 + 25200 = 840·T₂ + 90·T₂

29700 = 930·T₂

T₂ = 29700/930 = 31.94°.

The final temperature = 31.94°.

Explanation:

[tex]centripetal \: force = \frac{m {v}^{2} }{r} [/tex]

Centripetal force = 45 * 2 = 90 N

Therefore, centripetal force acting on a 45 kg boy riding in one of the cars when the car is on the top of the ferris wheel is 90 N.

The force exerted by the seat on the boy when the car is at the top of the ferris wheel is a centrifugal (pseudo force) acting (since the since the seat is in non- inertial frame) in exact opposite direction (Outwards) as the centripetal force and is equal in magnitude.

Answer:

β 2 = 0.02575 mm

Explanation:

given data

wavelength = 563 nm

separation distance between adjacent bright fringes =  0.0290 mm

wavelength = 500 nm

solution

we get here separation distance between adjacent bright fringes that is express as

β = [tex]\frac{\lambda D }{d}[/tex]    ..................................1

here D is distance from plane of slit to screen

and d is slit sepation that is constant

so

[tex]\frac{\beta 1}{\beta 2} = \frac{\lambda 1}{\lambda 2}[/tex]  

β 2 = [tex]\frac{500}{563} \times 0.0290[/tex]  

β 2 = 0.02575 mm

Answer:

Explanation:

Initial velocity (u) of the Bullet = 400 m/sec

Final velocity (v) of the Bullet = 100 m/sec

Bullet passed through the block in (t) = 0.0004 sec  

Using 1st Equation of motion :

400 m/s = 100 m/s - a (0.0004)

Deceleration of Bullet = 750,000 m/sec^2

(a) F (force exerted by the wooden block on the bullet) = F (force exerted by the bullet on the wooden block)

F = m * a = 0.008 * 750,000 = 6000 N

(b) Using 3rd Equation of motion :

[tex]v^{2} = u^{2} - 2aS[/tex]

10000 = 160000 - 2 * 750,000 * S

Thickness of wood (S) = 0.1 m

Answer:

Matter can be identified through its properties. One clue to helps us identify matter is magnetism. Magnetism is the ability of a material to be attracted by a magnet. Only certain materials are attracted to magnets, like iron, nickel, and cobalt.

Explanation:

we can identify matter by:  physical properties  and

chemical properties

Answer:

I guess i would say the microscope

Explanation:

Because of the microscope, we can see the cells.

Answer:

C) 1.5 A

Explanation:

P = IV

180 W = I (120 V)

I = 1.5 A

Answer:

is the last one, a magnetic wave and electrical current moving in opposite directions

Explanation:

opposite directions always attract in magnetic waves and fields

Answer:

integumentary, skeletal, muscular, nervous, endocrine, cardiovascular, lymphatic, respiratory, digestive, urinary, and reproductive

Explanation:

and this is biology not physics

Answer:

The answer is False.

Explanation: The FDA (food and drug administration) is a regulatory agency of the United state Government, they regulate the production and distribution of food and drugs within the United States of America, ensuring that standards are met and followed.

Most of the approvals given to food and drugs by FDA are done based on random sampling of products which may not be able to capture all the defective products in a given lot or batch of supplies, which is why it very necessary to take other measures to verify the wholesomeness, authenticity etc of a given product before purchasing or making use of such products.

Answer:

false

Explanation:

got right on egd

Answer:

The reading of the vernier calliper is 3.93 mm

Explanation:

The given instrument is a micrometer screw gauge that has a main scale reading and a vernier scale reading

The the question, we have;

The individual divisions of the main scale = 0.5 mm

The reading on the main scale = 3.5 mm

The reading on the vernier scale = 43

The accuracy of the vernier caliper = 0.01

Reading on the vernier scale multiplied by the accuracy of the vernier caliper = 43 × 0.01 = 0.43 mm

The reading of the micrometer screw gauge = The reading on the main scale + Reading on the vernier scale multiplied by the accuracy of the vernier caliper

Therefore, the reading of the micrometer screw gauge = 3.5 + 0.43= 3.93 mm

The reading of the vernier calliper = 3.93 mm.

Answer:

1.7 BTU

Explanation:

q = mCΔT

q = (25 g) (0.9 J/g/°C) (100°C − 20°C)

q = 1800 J

q = 1800 J × (1 BTU / 1055 J)

q = 1.7 BTU

Answer:

Distance covered 28 km

displacement is 22.8 km North-East

Explanation:

Distance shows how far apart objects or points are from each other. The distance he covered is the sum of all the distance travelled. Therefore:

Distance covered = 12 km + 6 km + 10 km = 28 km

Displacement is a vector quantity (has direction). It is the overall change in position.

The total distance traveled north = 12 km + 10 km = 22 km

The distance traveled east = 6 km

The displacement (d) is:

d² = 22² + 6² = 484 + 36

d² = 520

d = √520 = 22.8 km

Therefore the displacement is 22.8 km North-East

Distance covered 28 km

displacement is 22.8 km North-East

Distance covered

= 12 km + 6 km + 10 km

= 28 km

Now

The total distance traveled north = 12 km + 10 km = 22 km

And,  

The distance traveled east = 6 km

So,  

The displacement (d) is:

[tex]d^2 = 22^2 + 6^2\\\\ d^2 = 520\\\\d = \sqrt520[/tex]

= 22.8 km

learn more: https://brainly.com/question/10813422?referrer=searchResults

Answer:

it will be 8ms-1

Explanation:

MaUa+MbUb=MaVa+MbVb

Answer:

Inference

Explanation:

An inference involves the application of logic to progress from a premise to a conclusion or logical consequence on the basis of the evidence or known fact. Inference is a process of thought that be divided into a deduction and an induction aspect.

In the given question Halley, by standing outside was able to deduce the sound of thunder she is then able by inductive reasoning from the fact that storms are usually preceded by and accompany lightening, conclude that there is a storm coming.

Answer:

speed=330m/s

Explanation:

the speed of wave is given as

speed(meter per second) =frequency(hertz) * wavelength(meters)

so using the above formula we substitute the figures given in the question in the formula we get

speed = 0.4*825

speed =330m/s

note m/s is the si unit for speed which is read as meter per second

therefore speed =330m/s

Answer:

The output force would decrease since exerted force is inversely proportional to contact area.

Explanation:

F ∝ [tex]\frac{1}{A}[/tex] , Where 'F' is the exerted force and 'A' is the contact area.

Find answers and explanations in the attachments

Answer:

Explanation:

) (C) Suppose the piston is fixed. Find the energy input required to raise the temperature to 700 K.

Explanation:

It is given that,

The distance covered by a body along the x-axis is given by :

[tex]x=2t^3+5t^2+t[/tex]

t is in seconds and x is meters

Speed of the body is given by :

[tex]v=\dfrac{dx}{dt}\\\\v=\dfrac{d(2t^3+5t^2+t)}{dt}\\\\v=6t^2+10t+1[/tex]

At t = 0,

[tex]v=6(0)^2+10(0)+1=1\ m/s[/tex]

At t = 2 s,

[tex]v=6(2)^2+10(2)+1=45\ m/s[/tex]

So, the average speed in a time interval from t= 0s and t=2s is 45 m/s.

Answer:

The collapse of a protostar with less than 0.08 times the mass of the Sun is halted by DEGENERACY PRESSURE. b. As a protostar shrinks in size, its central temperature rises along with its THERMAL PRESSURE. c. A star that has not yet finished forming is called a__PROTOSTAR_____. d. A forming star spins more rapidly as it collapses because of conservation of ANGULAR MOMENTUM. e. If a protostar has a mass too small for it to sustain nuclear fusion it becomes the type of object known as a____BROWN DWARF____

Answer:

60.00

Explanation:

you welcome

Answer:

2,500,000W or 2.5MW

Explanation:

The power lost due to resistance is given by I^2R. We must first obtain R as follows;

Resistance per kilometer= 0.050Ω/km

Distance covered= 200km

R = 200km x 0.050Ω/km = 10Ω

The lost power as a 500A current passes through the powerline is:

P = I²R

P= 500² x 10

P= 2,500,000 W or 2.5MW

The resistive power loss in 200 km of the powerline is of 2.5 MW.

Given data:

The root mean square voltage is, V' = 500000 V.

The magnitude of current through the power line is, I =500 A.

The magnitude of resistance of cable is, R = 0.050 Ω/km.

The length of powerline is, L = 200 km.

Whenever there is a flow of current through the wire, then there are various losses out of which the power loss is a major factor. The mathematical expression for the power loss is given as

P = I²R

Solving as,

P= 500² x 10

P= 2,500,000 W or 2.5MW

Thus, we can conclude that the resistive power loss in 200 km of the powerline is of 2.5 MW.

Learn more about the resistive power loss here:

https://brainly.com/question/15158529

Explanation:

Assuming the 10 m distance is the vertical displacement, the work done by both people is the same.

Work = force × distance

W = (250 N) (10 m)

W = 2500 J

The power of the first person is:

Power = work / time

P = 2500 J / 120 s

P = 20.83 W

The power of the second person is:

P = 2500 J / 60 s

P = 41.67 W

Explanation:

Given that,

Number of loops are 3

Length of slinky is 3.75 m

They time 20 oscillations in  6.73 s.

We need to find the wavelength of  the standing wave.

For 3 loops, [tex]L=\dfrac{3\lambda}{2}[/tex]

Here, [tex]\lambda[/tex] is the wavelength of the standing wave

So,

[tex]\lambda=\dfrac{2L}{3}\\\\\lambda=\dfrac{2\times 3.75}{3}\\\\\lambda=2.5\ m[/tex]

So, the wavelength of the standing wave is 2.5 m.

Answer:

Electronic tools provide more accurate data and this data is more efficient fast and easy to understand

Hope this helps you!!

Answer: Some of the ways to control noise pollution are as follows: (1) Control at Receiver's End (2) Suppression of Noise at Source (3) Acoustic Zoning (4) Sound Insulation at Construction Stages (5) Planting of Trees (6) Legislative Measures.

Answer:

You have to:

a) Improve your insulation.

b) Install a fence

c) Use modern Acoustic wall panels

d) Plant trees

e) Reduce electronic volumes,e.t.c.

Explanation:

okay.

Answer:

The work done is -176.4 J.

Explanation:

Given that,

Mass = 1.0 kg

An elevation of  2 m to an elevation of 20 m.

Suppose,  Find the work done by the gravitational field of the earth?

We need to calculate the force

Using formula of force

[tex]F=mg[/tex]

Put the value into the formula

[tex]F=1.0\times9.8[/tex]

[tex]F=9.8\ N[/tex]

We need to calculate the displacement

Using formula of displacement

[tex]Displacement = s_{2}-s_{1}[/tex]

[tex]s=20-2=18\ m[/tex]

The direction of displacement is upward.

Since gravitational force is downwards and displacement is upwards,

Then the angle is 180°.

We need to calculate the work done

Using formula of work

[tex]W=f\cdos s\cos\theta[/tex]

[tex]W=9.8\times18\cos180[/tex]

[tex]W=-176.4\ J[/tex]

Hence, The work done is -176.4 J.

Explanation:

Given that,

Initial speed of the bus, u = 0

Acceleration of the bus, a = 0.5 m/s²

Let v is the velocity at the end of 2 minutes. The change in velocity divided by time equals acceleration.

So,

[tex]a=\dfrac{v-u}{t}\\\\v=u+at\\\\v=0+0.5\times 120\\\\v=60\ m/s[/tex]

Let d is the distance cover during that time. So,

[tex]v^2-u^2=2ad\\\\d=\dfrac{v^2-u^2}{2a}\\\\d=\dfrac{(60)^2}{2\times 0.5}\\\\d=3600\ m[/tex]

So, the final speed is 60 m/s and the distance covered during that time is 3600 m.