The rock falls from the distance of 15 m before it hits the water. Calculate its kinetic energy just before hitting the water. Show your working

Answer:

5 m

Explanation:

We'll begin by calculating the original potential energy. This can be obtained as follow:

Mass (m) = 0.2 Kg

Height (h) = 20 m

Acceleration due to gravity (g) = 10 m/s²

Energy (E₀) =?

E₀ = mgh

E₀ = 0.2 × 10 × 20

E₀ = 40 J

Next, we shall determine the new energy of the ball.

Energy (E₀) = 40 J

Energy lost (Eₗ) = 30 J

New energy (E) =?

E = E₀ – Eₗ

E = 40 – 30

E = 10 J

Finally, we shall determine height of the ball on rebound. This can be obtained as follow:

New energy (E) = 10 J

Mass (m) = 0.2 Kg

Acceleration due to gravity (g) = 10 m/s²

Height (h) =?

E = mgh

10 = 0.2 × 10 × h

10 = 2 × h

Divide both side by 2

h= 10 / 2

h = 5 m

Thus, the height of the ball on rebound is 5 m

Answer:

R = 4.77 ohms

Explanation:

Four resistors are given such that,

R₁ = 2 ohms

R₂ = 3 ohms

R₃ = 5 ohms

R₄ = 10 ohms

Here, R₁ and R₂ in series. The equivalent is given by :

R₁₂ = R₁ + R₂

= 2 + 5

R₁₂ = 7 ohms

Similarly, R₃ and R₄ are in series. so,

R₃₄ = R₃ + R₄

= 10+5

R₃₄ = 15 ohms

Now, R₁₂ and R₃₄ are in parallel. So,

[tex]\dfrac{1}{R}=\dfrac{1}{R_{12}}+\dfrac{1}{R_{34}}\\\\\dfrac{1}{R}=\dfrac{1}{7}+\dfrac{1}{15}\\\\R=4.77\ \Omega[/tex]

So, the equivalent resistance s 4.77 ohms.

Answer:

La persona pesa menos

Explanation:

Generalmente, definimos el peso como la fuerza gravitacional que actúa sobre un objeto.

Dado que la constante gravitacional depende del cuadrado de la distancia medida desde el centro de la Tierra, podemos concluir que el peso de un objeto disminuye a medida que aumenta la distancia entre el objeto y el centro de la Tierra (mayor altitud).

Por lo tanto, la persona que pesa 700 N al nivel del mar pesará menos cuando esté en un avión a una altitud de 10,000 m.

Answer:

it is maybe A but i'm not 100% sure

Explanation:

its the only one that is mixed

ya ok do ok bro al ya al ya la ya al

Answer:

Uranium

Explanation:

The most important in atomic research is Uranium, Uranium Can be used as fuel for nuclear power plants and the nuclear reactors that run naval ships and submarines, so option A is correct.

The atom is the smallest unit of matter that may be divided without generating particles with an electrical charge. Additionally, it is the tiniest material with characteristics similar to chemical elements. As a result, the atom acts as the basic building block of chemistry.

Space makes up the majority of an atom. The rest is made up of a positively charged nucleus made up of protons and neutrons that are surrounded by a cloud of negatively charged electrons. The nucleus is small and dense when compared to electrons, which are the lightest charged particles in nature. Electric forces, link electrons to the nucleus of atoms, causing them to be drawn to any positive charge.

Uranium that has been "enriched" to have a higher concentration of U-235 can power nuclear power plants, and It can also be applied to nuclear weapons.

Therefore, uranium is the most important in atomic research.

To know more about atoms:

https://brainly.com/question/13518322

#SPJ2

Answer:

Answer:

.04 kg m/s

Explanation:

Momentum is simply mass multiplied by velocity given by p = mv. You can consider momentum as mass in motion.

Before the collision, the data given for the toy train:

v = 0.5m/s

m = 75g

We need to convert grams into the SI unit of mass, kg.

75g / 1000g * 1kg = 0.075kg

Using p = mv, we can determine:

p = 0.075kg * 0.5m/s = 0.0375 kg m/s

Rounding to the value of 1 sig-fig, it comes out to be 0.04 kg m/s.

Answer:

HOPE IT HEPLED U !!!!

Explanation:

i think it's (C) They have different units ....

Answer:

40000 N/m²

Explanation:

Applying,

P =  F/A................... Equation 1

Where P = Pressure, F = Force, A = Area.

From the question,

The force(F) exerted by the person's foot is thesame as it's weight.

F = W = mg............ Equation 2

Where m = mass of the person, g = acceleration due to gravity.

Substitute equation 2 into equation 1

P = mg/A................ Equation 3

Given: m = 60 kg, g = 10 m/s², A = 150 cm² = (150/10000) m² = 0.015 m²

Substitute these values into equation 3

P = (60×10)/0.015

P = 600/0.015

P = 40000 N/m²

The average velocity is 25 mph north.

Average velocity = displacement/time

Displacement =

(400 mi north) + (275 mi south)

Displacement = 125 mi north

Average V = (125 mi north) / 5 hours.

Average V = 25 mph north

Answer:

The correct answer is - none of the above.

Explanation:

Cell membranes or plasma membranes of the cell are composed mainly of fatty-acid-based lipids and proteins. Membrane lipids are of two types majorly, glucolipids, phospholipids, and sterols (generally cholesterol).

Sphingolipids are also a structural component of the cell membrane that helps in segregation into distinct membrane domains. Glycolipids are present on the surface of the plasma membrane.

Answer:

Velocidad en m / s = 72,25 m / s

Explanation:

Dado

Distancia a recorrer por el coche de carreras = 87 Km

1 km = 1000 m

Por lo tanto, 87 km = 87000 m

Tiempo necesario para viajar 87 km / 87000 metros = 20 minutos o 20 * 60 = 1200 segundos

Velocidad en m / s = 87000/1200

Velocidad en m / s = 72,25 m / s

Answer:

400J

Explanation:

The work done by the force on the object is 80 J.

The work is defined by the product of force and displacement. Its unit of measurement is joule. And the formula is,

Work = Force ×Displacement

Or mathematically it is W = F.d

     [tex]F = 20N , d = 4m\\[/tex]

       W = 20 × 4

       W = 80 J

Hence the work done by the force is 80J.

Find out more information about work here:

https://brainly.com/question/11367798    

#SPJ2

Explanation:

tan(theta)=(v^2)/(length of string × g)

=(1.4^2)/(0.84 × 9.8m/s )

=1.96/(8.232)

=0.2380952381

theta=arctan(0.2380952381)

=13.4°

Answer:

The answer is Current.

Answer:

451.13 J/kg.°C

Explanation:

Applying,

Q = cm(t₂-t₁)............... Equation 1

Where Q = Heat, c = specific heat capacity of iron, m = mass of iron, t₂= Final temperature, t₁ = initial temperature.

Make c the subject of the equation

c = Q/m(t₂-t₁).............. Equation 2

From the question,

Given: Q = 1500 J, m = 133 g = 0.113 kg, t₁ = 20 °C, t₂ = 45 °C

Substitute these values into equation 2

c = 1500/[0.133(45-20)]

c = 1500/(0.133×25)

c = 1500/3.325

c = 451.13 J/kg.°C

Answer:

Explanation:

[tex]E=\frac{q}{F}[/tex] where q is the charge of the electron and F is the electrostatic force. Filling in:

[tex]E=\frac{-1.6*10^{-19}}{9.2*10^{-15}}[/tex] which gives you an electric field magnitude of

E = -1.7 × [tex]10^{-5[/tex] C/N

Answer:

(a) 0.71 mm

(b) 0.158 cubic cm

Explanation:

The width of one wire is the diameter of the wire.

(a) Let the diameter of each wire is d.

So, 10 d = 14.2 mm

d = 1.42 mm

radius of each wire, r = d/2 = 1.42/2 = 0.71 mm

(b) Length, L = 10 cm

The volume of the single wire is given by

[tex]V =\pi\times r^2\times h \\\\V =3.14\times 0.071^2\times 10\\\\V =0.158 cm^3[/tex]

Answer:

Hello There!!

Explanation:

1/2R because wire B has twice the radius,it has four times the cross-sectional area of wire A.

hope this helps,have a great day!!

~Pinky~

Answer:

Satellite D

Explanation:

It has more mass

Option C: Later in the day, less power is developed in lifting each box

Answer:

Later in the day, less power is developed in lifting each box.

power= workdone÷time

Answer:

Nitric acid, also known as aqua fortis and spirit of niter, is a highly corrosive mineral acid. The pure compound is colorless, but older samples tend to acquire a yellow cast due to decomposition into oxides of nitrogen and water. Most commercially available nitric acid has a concentration of 68% in water.

Explanation:

Good morning...

Nitric acid production is mainly driven by fertilizer industry. Nitric acid is used in the production of ammonium nitrate and calcium ammonium nitrate which find applications as fertilizers.

Answer:

I think C

Explanation:

If im right give brainliest :)

Answer:

false

Explanation:

sana po maktulong

Answer:

B. When the independent variable composed of categories and does not show a relationship to the dependent variable

Explanation:

A bar graph, is a graph used for presenting data grouped into categories, which are the independent variables of the graph, and the measurement of each category, which are represented as rectangular bars having lengths proportional to the value of the category, on a chart

In the bar graph or chart, there is no direct relationship between the categories, which are the x-values and the dependent variables , which are the length of the bars, the y-values, as the length of the rectangular bar in one category, cannot be obtained from another category through a relationship

Therefore, the correct option is option is when the independent variable composed of categories and does not show a relationship to the dependent variable

(B)

Explanation:

[tex]pe = \frac{1}{2} k {x}^{2} [/tex]

The equation of the elastic potential energy stored in the spring can be represented as: EPE = (1/2)kx². Therefore, option (B) is correct.

The elastic potential energy can be described as the total energy obtained as a result of deformation in the shape of an object. The elastic potential energy implies any object which is capable of regaining its actual shape and size after deformation.

The deformation is only possible as a result of the gained potential energy which is called the elastic potential energy. The elastic potential energy can be stored energy of a compressible or stretchable in other words stored energy of perfectly elastic materials.

The mathematical equation of the elastic potential energy formula is given by:

U = 1/2 (Force × Displacement)

U = (1/2) (kx) (x)

U = (1/2)kx²

Where k is the spring constant and x is the displacement as a result of applied external force.

Learn more about elastic potential energy, here:

https://brainly.com/question/14687790

#SPJ2

Answer:a gas at pressure of 0.8 m column of H g

Answer:

(D) 50 W​

Explanation:

Given the following data;

Mass = 5 kg

Force = 100 N

Distance = 60 N

Time = 2 minutes

Conversion:

1 minute = 60 seconds

2 minutes = 60 * 2 = 120 seconds

To find the power output required to push the box;

First of all, we would determine the work done in pushing the box.

Work done = force * distance

Workdone = 100 * 60

Workdone = 6000 Joules

Next, we find power output;

Power = workdone/time

Power = 6000/120

Power = 50 Watts