claculate the pressure exerted by the water on the bottom of a deep dam of 12m from its surface .(density of water =1000kg/m sqare)​

Answer:

22.2 m/s or 80 km/h

Explanation:

Given that

Distance travelled by the car, d = 240 km

Time taken by the car, t = 3 hours.

Speed of the car, v = ? m/s

for easy calculations, we will be converting the units to meters and seconds respectively.

240 km to meters would be

240 * 1000 m = 240000 m

3 hrs to seconds would be

3 * 60 mins * 60 seconds = 10800 s

now, we have our distance and time to be

d = 240000 m

t = 10800 s

speed is defined as the ratio of distance with respect to time taken, effectively,

Speed = distance/time

speed, v= 240000 / 10800

v = 22.2 m/s

therefore, the speed of the car during the time is 22.2 m/s, or if the speed is needed in km/h, we can convert it

22.2 * 3600/1000 =

80 km/h

Answer:

1) It means that the acceleration is 0

2) Momentum, p = Mass, m × Velocity, v

3) Newton's second law of motion

4) The conditions where there are no resultant forces acting on the object

Explanation:

1) The value v - u =  0 means that the acceleration is 0

The relation between v and u is v = u + a·t

v - u = a·t

When v - u = 0 we have;

a·t = 0

a = 0 or t = 0

Acceleration, a = 0

2) The relation between momentum, mass and velocity is

Momentum, p = Mass, m × Velocity, v

p = m × v

3) The bus moving a little distance forward even when the breaks are applied is due to the following relation;

Force = Rate of change of momentum produced

Which is Newton's second law of motion

Therefore, where the the force is low, the rate of change of the momentum and therefore, the velocity will be low, and the bus will still move further after applying the breaks

4) According to Newton's first law of motion, the conditions under which the acceleration of a moving object will be zero includes conditions where there are no resultant forces acting on the object.

Answer:

Option D (Electricity can flow through it under special conditions ) seems to be the correct choice.

Explanation:

Other options that are provided are not related to the given theory. So that the above would be the correct choice.

Statement "Lack free electrons that can move to other atoms " describe semi-conductor.

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Answer:

a) Strings of guitar (being played)

b) Heart-beat in a healthy person

c) Motion of an apple falling from a tree

Explanation:

a) The motion of the string of a guitar being played is the only motion involving simple harmonic motion.

b) All the other motions are circular motion except the heart beat in a healthy person, which is periodic.

c) The motion of an apply falling from a tree is the only motion under the complete influence of gravity from the onset till the end.

Answer:

Explanation:

[tex]m =800kg\\v = 15\\\\K.E = \frac{1}{2}mv^2\\ K.E= \frac{1}{2} \times 800\times 15^2\\= 400 \times 225\\= 90000 joules\\= 90 kilojoules[/tex]

Answer:

lathe

perfectly symmetrical

Answer: A lathe is used to turn wood . It rotates and carves wood to produce a perfectly symmetrical form .

First one is lathe .

Second one is perfectly symmetrical .

Explanation: I just took the test on Plato and had 100%

Answer:

8 atm

Explanation:

Ideal gas law:

PV = nRT

where P is pressure, V is volume, n is moles, R is universal gas constant, and T is absolute temperature.

If n is constant:

PV / T = PV / T

(4 atm) (60 L) / (27 + 273) K = P (40 L) / (127 + 273) K

0.8 atm = 0.1 P

P = 8 atm

Answer:

The volume of the cylinder is [tex]653.71\ \text{cm}^3[/tex]

Explanation:

Given that,

The height of the cylinder is 13 cm

Radius of the cylinder is 4 cm

We need to find the volume of the cylinder. The formula that is used to find the volume of a cylinder is given by :

[tex]V=\pi r^2 h\\\\V=\dfrac{22}{7} \times (4)^2 \times 13\\\\V=653.71\ \text{cm}^3[/tex]

So, the volume of the cylinder is [tex]653.71\ \text{cm}^3[/tex]

Answer:

653.45 is the answer

Explanation:

This question is incomplete; here is the complete question:

Marco is conducting an experiment. He knows the wave that he is working with has a wavelength of 32.4 cm. If he measures the frequency as 3 hertz, which statement about the wave is accurate?

A. The wave has traveled 32.4 cm in 3 seconds.

B. The wave has traveled 32.4 cm in 9 seconds.

C. The wave has traveled 97.2 cm in 3 seconds.

D. The wave has traveled 97.2 cm in 1 second.

The answer to this question is D. The wave has traveled 97.2 cm in 1 second.

Explanation:

The frequency of a wave, which is in this case 3 hertz, represents the number of waves that go through a point during 1 second. According to this, if the frequency of the wave is 3 hertz this means in 1 second there were 3 waves. Moreover, if you multiply the wavelength (32.4cm) by the frequency (3) you will know the distance the wave traveled in 1 second: 32.4 x 3 =  97.2 cm. This makes option D the correct one as the distance in 1 second was 97.2 cm.

Answer:Is D!

Explanation:TEAT(Sorry) -_-*

Answer:

The law of conservation of momentum states that the total momentum of interacting objects does not change. This means the total momentum before a collision or explosion is equal to the total momentum after a collision or explosion.

Answer:

The answer is

Explanation:

Change. Does not change.means.

Hope this helps....

Have a nice day!!!!

Millimeters, centimeters, meters, kilometers, inches, feet, and miles are all examples of unit of length like: distance between two points  and displacement of any object.

Meter is  a Si unit of length whereas centimeter is CGS unit of length and  Feet is FPS unit of lengths. Another units are also useful in measuring lengths.

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Answer:

A. It is always a positive force

Explanation:

Hooke's law describes the relation between an applied force and extension ability of an elastic material. The law states that provided the elastic limit, e, of a material is not exceeded, the force, F, applied is proportional to the extension, x, provided temperature is constant.

i.e F = - kx

where k is the constant of proportionality, and the minus sign implies that the force is a restoring force.

The applied force can either be compressing or stretching force.

Answer:

option a is correct

Explanation:

water ∠iron∠aluminium∠mercury

water density =1.0000

iron =7.487

aluminium=2.07

mercury=13.59

Answer: D

Explanation:

Given that a car travels from point A to B in 3 hours and returns back to point A in 5 hours. Points A and B are 150 miles apart along a straight highway.

From point A to B

The speed = distance / time

Where

Distance = 150 mile

Time = 3 hours

Substitute the values into the formula

Speed = 150/3 = 50 mile/ hours

From Point B to Point A

Distance = 150 miles

Time = 5 hours

Where speed = distance/ time

substitute all the parameters into the formula

Speed = 150/5 = 30 mph

Therefore, The car travels at 50 mph for the first half and 30 mph for the second half.

The correct answer is option D

Answer:

800km/s

Explanation:

Initial momentum = final momentum

the total momentum is zero, Before the release of the asteroid , but Superman and the asteroid are not moving.

So, according to the Conservation of momentum the total momentum when the astronaut is been thrown will equals to zero . Then we can say

Initial momentum = final momentum

Because the momentum of the Superman immediately the asteroid is been thrown is equal to the momentum of the asteroid

Momentum =(mass ×velocity)

the mass of the asteroid i= 1000M

Given velocity = 800 m/s,

momentum =(1000M)(800 m/s)

= 800,000M m/s.

to get the answer, we need to divide by Superman's mass, M, which gives his recoil velocity of 800,000 m/s.

But we're told to convert to km/ s

We know that 1m/s=0.001km/s

=(800,000M m/s)× (0.001km/s)

=800km/s

Therefore, his recoil speed (in km/s) is 800km/s

Answer:

Height of pole = Height of giraffe

Explanation:

Given:

Height of giraffe = 20 ft

Height of pole = 240 inch

Find:

Which is taller

Computation:

Height of giraffe = 20 ft

We know that 1 ft = 12 inch

So,

Height of giraffe = 20 × 12 inch

Height of giraffe = 240 inch

and

Height of pole = 240 inch

Height of pole = Height of giraffe

Answer:

We have the position vector given in terms of time t. r(t) = t^3*i + t^2*j

To find the velocity vector we have to differentiate r(t) with respect to time.

r'(t) = 3t^2*i + 2t*j

The vector representing acceleration is the derivative of the position vector

r''(t) = 6t*i + 2*j

When time t = 2.

The velocity vector is 3*2^2*i + 2*2*j

=> 12*i + 4*j

The speed is the absolute value of the velocity vector or sqrt(12^2 + 4^2) = sqrt (144 + 16) = sqrt 160

The acceleration vector is 6*2*i + 2*j

=> 12*i + 2*j

The required acceleration at t=2 is 12*i + 2*j and the speed is sqrt 160.

Explanation:

Can I have thx and brainliest?

Answer:

The difference between One-way as well as reversible rotary motion​ is described below.

Explanation:

Answer: Bleach is a base

Explanation:  If bleach had a pH level of 12, a number above 7, than it is a base.  Hope this helps!

Answer:

Explanation:

Average rate = gallons / minutes

If 12.5gallons in 5mins

Xgallons in 1mins

12.5/5 = 2.5gallons per minute

6. Force

7 speed

8 distance

9 acceleration

Answer:

we learned that an object that is vibrating is acted upon by a restoring force. The restoring force causes the vibrating object to slow down as it moves away from the equilibrium position and to speed up as it approaches the equilibrium position. It is this restoring force that is responsible for the vibration. So what forces act upon a pendulum bob? And what is the restoring force for a pendulum? There are two dominant forces acting upon a pendulum bob at all times during the course of its motion. There is the force of gravity that acts downward upon the bob. It results from the Earth's mass attracting the mass of the bob. And there is a tension force acting upward and towards the pivot point of the pendulum. The tension force results from the string pulling upon the bob of the pendulum. In our discussion, we will ignore the influence of air resistance - a third force that always opposes the motion of the bob as it swings to and fro. The air resistance force is relatively weak compared to the two dominant forces.

The gravity force is highly predictable; it is always in the same direction (down) and always of the same magnitude - mass*9.8 N/kg. The tension force is considerably less predictable. Both its direction and its magnitude change as the bob swings to and fro. The direction of the tension force is always towards the pivot point. So as the bob swings to the left of its equilibrium position, the tension force is at an angle - directed upwards and to the right. And as the bob swings to the right of its equilibrium position, the tension is directed upwards and to the left. The diagram below depicts the direction of these two forces at five different positions over the course of the pendulum's path.

that's what I know so far

Answer:

1. Tienes 1 kg de fruta.

2. Queda por recorrer 1/4 km.

3. Ambos pesan lo mismo.

Explanation:

1. Tienes 1/2 kg y cuando te doy 1/4 te queda:

[tex] m = \frac{1}{2} - \frac{1}{4} = \frac{1}{4} [/tex]

Ahora cuando te doy 3/4 kg te queda en total:

[tex] m_{T} = \frac{1}{4} + \frac{3}{4} = 1 kg [/tex]

Por lo tanto, tienes 1 kg de fruta al final.

2. Si falta por recorrer la mitad de la mitad, tenemos:

[tex] d = \frac{1/2}{2} = \frac{1}{4} [/tex]

Entonces, queda por recorrer 1/4 km.

3. El peso (P) del hierro es:

[tex] P = m*g [/tex]    

[tex] P = (1 + 1/2)kg*9.81 m/s^{2} = 14.72 N [/tex]

Y el peso de la paja es:

[tex] P = 3/2 kg*9.81 m/s^{2} = 14.72 N [/tex]

Por lo tanto, ambos pesan lo mismo.

Espero que te sea de utilidad!

Answer:

Iron expands because heating increases the space between the molecules

Explanation:

According to the kinetic molecular theory, all matter is composed of atoms and molecules which are in constant motion.

When a substance is heated, molecules of the substance begin to vibrate faster. This faster vibration leads to increased space between the molecules (expansion) . The kind of motion motion and degree of spacing of the molecules determine the state of matter in which the substance is found.

Hence, when an iron bar is heated, it expands due to increased motion of its molecules leading to spaces between them.

Answer:

Average acceleration = Displacement / (time)^2

Explanation:

The unit for acceleration is

[tex]m {s}^{ - 2} [/tex]

Displacement = m

Time = s

Hence the units of displacement and time should be manipulated to get the unit of acceleration.

You can't. You can only find average velocity.

But if you also know that initial velocity is zero ... the object started from rest ... then

Avg acceleration =

2 x displacement / time-squared

Answer:

17.15 m

Explanation:

Assuming the well is empty (full of air instead of water), the speed of sound is v = 343 m/s.

The water well acts as a pipe closed at one end.  Therefore, the depth of the water well must be an odd multiple of a quarter of the resonant wavelength.

L = (2n − 1) λ/4, n = 1, 2, 3, etc.

v = λf, so λ = v/f.  Substituting:

L = (2n − 1) v/(4f)

Solving for frequency:

f = (2n − 1) v/(4L)

The difference between two successive resonant frequencies is therefore:

Δf = (2(n+1) − 1) v/(4L) − (2n − 1) v/(4L)

Δf = (2n + 1) v/(4L) − (2n − 1) v/(4L)

Δf = 2 v/(4L)

Δf = v/(2L)

Plugging in values:

50 Hz − 40 Hz = 343 m/s / (2L)

2L = 34.3 m

L = 17.15 m

Answer: React with the skin

Explanation:

lab safety test Safety goggles and an apron must be worn when handling chemicals labeled corrosive because they React with the skin

Answer:

(I). The Schwarzschild radius is [tex]2.94\times10^{8}\ km[/tex]

(II). The Schwarzschild radius is 17.7 km.

(III). The Schwarzschild radius is [tex]1.1\times10^{-7}\ km[/tex]

(IV). The Schwarzschild radius is [tex]7.4\times10^{-29}\ km[/tex]

Explanation:

Given that,

Mass of black hole [tex]m= 1\times10^{8} M_{sun}[/tex]

(I). We need to calculate the Schwarzschild radius

Using formula of radius

[tex]R_{g}=\dfrac{2MG}{c^2}[/tex]

Where, G = gravitational constant

M = mass

c = speed of light

Put the value into the formula

[tex]R_{g}=\dfrac{2\times6.67\times10^{-11}\times1\times10^{8}\times1.989\times10^{30}}{(3\times10^{8})^2}[/tex]

[tex]R_{g}=2.94\times10^{8}\ km[/tex]

(II). Mass of block hole [tex]m= 6 M_{sun}[/tex]

We need to calculate the Schwarzschild radius

Using formula of radius

[tex]R_{g}=\dfrac{2MG}{c^2}[/tex]

Put the value into the formula

[tex]R_{g}=\dfrac{2\times6.67\times10^{-11}\times6\times1.989\times10^{30}}{(3\times10^{8})^2}[/tex]

[tex]R_{g}=17.7\ km[/tex]

(III). Mass of block hole m= mass of moon

We need to calculate the Schwarzschild radius

Using formula of radius

[tex]R_{g}=\dfrac{2MG}{c^2}[/tex]

Put the value into the formula

[tex]R_{g}=\dfrac{2\times6.67\times10^{-11}\times7.35\times10^{22}}{(3\times10^{8})^2}[/tex]

[tex]R_{g}=1.1\times10^{-7}\ km[/tex]

(IV). Mass = 50 kg

We need to calculate the Schwarzschild radius

Using formula of radius

[tex]R_{g}=\dfrac{2MG}{c^2}[/tex]

Put the value into the formula

[tex]R_{g}=\dfrac{2\times6.67\times10^{-11}\times50}{(3\times10^{8})^2}[/tex]

[tex]R_{g}=7.4\times10^{-29}\ km[/tex]

Hence, (I). The Schwarzschild radius is [tex]2.94\times10^{8}\ km[/tex]

(II). The Schwarzschild radius is 17.7 km.

(III). The Schwarzschild radius is [tex]1.1\times10^{-7}\ km[/tex]

(IV). The Schwarzschild radius is [tex]7.4\times10^{-29}\ km[/tex]

The energy conservation allows to find the Schwarschild radius for several bodies of different masses are:

  1)  Black hole quasar is:  r = 2.9 10⁸ km

  2) Blsck hole supernove is:  r = 17.7 km

  3)  Mini black hole is:   r = 1.1 10⁻⁷ km

  4) Human body is:  r=  7 10⁻²⁹ km

The schwarschild radius is defined as the distance from a black hole center at radius  which the escape velocity is equal to the light speed, in some cases it is also called the event horizon.

Let's use Newton's second law where force is the universal law of attraction and acceleration is centripetal.

        F = ma

        F = [tex]G \frac{Mm}{r^2}[/tex]        

Where F is the force, M the mass of the black hole, m the handle of the body, r the radius and v the speed of the body.

The energy of the gravitational field is

        F = [tex]- \frac{dU}{dr }[/tex]  

         U = [tex]-G \frac{Mm}{r}[/tex]  

Let's use conservation of energy

        Em₀ = K + U = ½ m v² -  [tex]G \frac{Mm}{r}[/tex]  

In infinity the energy

        Em_f = 0

energy is conserved

       Em₀ = Em_f  

       ½ m v² - [tex]G \frac{Mm }{r}[/tex]  = 0

       r = [tex]\frac{2GM}{v^2}[/tex]

From the definition of the Schwarschild radius this speed is equal to the light speed

        v = c

        r = [tex]\frac{2GM}{c^2 }[/tex]  

They ask to calculate the radius for several cases of different mass, claculate the constant value

      V = [tex]\frac{2 \ 6.67 \ 10^{-11} }{(3 \ 10^8) ^2 }[/tex]  

      V =  1.482 10⁻²⁷

1) A black hole of mass M = 1 10⁸ [tex]M_{sum}[/tex]

The tabulated mass of the sun is [tex]M_{sum}[/tex] = 1.989 10³⁰ kg

Let's  substitute

        r =  1.482 10⁻²⁷   1 10⁸ 1.989 10³⁰

        r = 2.94 10⁸ km

With two significant figures

        r = 2.9 10⁸ km

2) A black hole of mass M = 6 [tex]M_{sum}[/tex]

        r =  1.482 10⁻²⁷ 6 1.989 10-30

        r = 17.7 km

3) a mini black hole with the mass of the moon

    Tabulated mass of the moon M = 7.35 10²² kg

       r =  1.482 10⁻²⁷  7.35 10²²    

       r = 1.1 10⁻⁷ km

4) A person of M = 50 kg

    r =  1.482 10⁻²⁷ 50

    r=  7 10-29 km

In conclusion using the conservation of energy we can find the Schwarschild radius for several bodies of different masses are:

  1)  Black hole quasar is:  r = 2.9 10⁸ km

  2) Blsck hole supernove is:  r = 17.7 km

  3)  Mini black hole is:   r = 1.1 10⁻⁷ km

  4) Human body is:  r=  7 10⁻²⁹ km

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