Why is accelration negative when velocity is positive.​

Answer:

Explanation:

s = s₀ + v₀t + ½at²

s = 0 + 0(15) + ½(6)(15²)

s = 675 m

Not sure what the free fall acceleration is needed for, but if the object is dropped from a high enough point, it will travel in 15 seconds

s = ½10(15²) = 2250 m  if air resistance is ignored

Answer:

coefficient of friction (μ) and normal force (N)

Answer: How hard the surfaces push together and the types of surfaces involved

Explanation:

Answer:

-48cm

Explanation:

For a convex lens f is +ve and V is +ve

Using the formula 1/f=1/v+1/u

u=12cm and f=16cm

1/16-1/12=1/v

1/v=-1/48

v=-48cm

The use of the wheel barrow in this case makes it a simple machine

A wheelbarrow is an illustration of a straightforward device that can simplify labour by lowering the force needed to move a large load. The wheel and axle and the lever are two basic machines that are used.

The wheelbarrow's wheel is made of an axle and wheel. The friction between the wheel and the ground is decreased by the wheel's rotation around the axle. It can also be seen as one of the classes of the lever.

Learn more about simple machine:https://brainly.com/question/10075890

#SPJ1

Answer:

make a pineapple schematic

Explanation:

The quantity of heat energy that must be transferred to 2.25 kg of brass to raise its temperature from 20 °C to 240 °C is 195030 J

First, we shall list out the given parameters from the question. This is shown below:

The quantity of heat energy that must be transferred can be obtained as follow:

Q = MCΔT

= 2.25 × 394 × 220

= 195030 J

Thus, we can conclude quantity of heat energy that must be transferred is 195030 J

Learn more about heat:

https://brainly.com/question/16398667

#SPJ1

Answer:

False.

Explanation:

If you throw a ball into the air, Earth exerts a force on the ball. Also, the ball in the air exerts a force on Earth.

This ultimately implies that, there is a force pair between the earth and the ball.

this is the correct answer

Answer:

Using Ohm's Law, we can calculate the voltage of the battery as V = IR = (4 A)(7 Ω) = 28 V.

The total resistance of the circuit is R = R₁ + R₂ + r, where r is the internal resistance of each element.

We know that R₁ = 14 Ω and R = 7 Ω, so we can solve for R₂:

R₂ = R - R₁ = 7 Ω - 14 Ω = -7 Ω

This is a negative resistance, which doesn't make sense physically. However, it indicates that there is an error in the problem or the calculations.

To find the internal EDS of the elements, we can use the equation:

V = ε - Ir

where V is the voltage of the battery, ε is the internal EDS of each element, I is the current flowing in the circuit, and r is the internal resistance of each element.

We know that V = 28 V, I = 4 A, and r = 6 Ω, so we can solve for ε:

ε = V + Ir = 28 V + (4 A)(6 Ω) = 52 V

Therefore, the internal EDS of each element is 52 V.

Answer:

The electromagnetic force.

Answer:

It is electrical force

Explanation:

i got it wrong on A P E X  with magnetic hope this helps!

Answer:

for the first interference m = 1   y = 2,839 10-3 m

for the second interference m = 2   y = 5,678 10-3 m

Explanation:

The double slit interference phenomenon, for constructive interference is described by the expression

                d sin θ = m λ

where d is the separation between the slits, λ the wavelength and m an integer that corresponds to the interference we see.

In these experiments in general the observation screen is L >> d, let's use trigonometry to find the angles

           tan θ = y / L

with the angle it is small,

          tan θ = sin θ / cos θ = sin θ

we substitute

         sin θ = y / L

         d y / L = m λ

the distance between the central maximum and an interference line is

        y = m λ L / d

let's reduce the magnitudes to the SI system

     λ = 546 nm = 546 10⁻⁹ m

     d = 0.25 mm = 0.25 10⁻³ m

let's substitute the values

      y = m 546 10⁻⁹ 1.3 / 0.25 10⁻³

      y =  m 2,839 10⁻³

the explicit value for a line depends on the value of the integer m, for example

for the first interference m = 1

the distance from the central maximum to the first line is y = 2,839 10-3 m

for the second interference m = 2

the distance from the central maximum to the second line is y = 5,678 10-3 m

Answer:

D. An employee receives a bonus at the end of the week for having the most sales that week.

Explanation:

Took the test

Answer:

below

Explanation:

The change in Kinetic Energy is equal to the work done

  KE = 1/2 mv^2

      Change in KE =   1/2 m (19^2 - 3.2^2) = 747.1 kjoules

Circular disc's moment of inertia around axis passing through mass and parallel to disc Icm=MR22

The phrase "moment of inertia" in physics refers to the precise calculation of a body's inertia with respect to rotation, or the resistance a body exhibits when a torque is applied to alter its rate of rotation around an axis (turning force).

It is a broad (additive) property: the moment of inertia for a point mass is equal to the mass squared by the perpendicular distance from the axis of rotation. Because it resists rotational motion, the moment of inertia is referred to as such and not as a moment of force.

Moment of inertia is the propensity of an object to continue rotating at a constant speed or in a condition of rest. More torque is needed to shift this state the higher the moment of inertia.

To learn more about moment of inertia refer to:

https://brainly.com/question/14460640

#SPJ1

Option A is true: the red liquid is the least dense.

When different liquids are poured into a container, they will typically separate based on their densities. Liquids with higher densities will sink to the bottom, while liquids with lower densities will float on top.

In the scenario described in the question, we are told that the liquids have separated into three distinct layers: green on the bottom, blue in the middle, and red on top. Based on this layering, we can infer that the red liquid must be the least dense, since it is floating on top of the other two liquids.

Similarly, we can infer that the blue liquid is denser than the red liquid, but less dense than the green liquid, since it is sandwiched between them. And we can infer that the green liquid is the most dense, since it is at the bottom.

Learn more about density of liquid here: https://brainly.com/question/31161935

#SPJ1

v = s/t

44 m/s = 3.5 m/t

t = 3.5 m : 44 m/s

t = 0.08 s

a = v/t

a = 44 m/s/0.08 s

a = 550 m/s²

a : g = 550 m/s² : 10 m/s²

a : g = 55 : 1

#LearnWithEXO

Answer:

Refer to the step-by-step Explanation.

Step-by-step Explanation:

Simplify the equation with given substitutions,

Given Equation:

\(mgh+(1/2)mv^2+(1/2)I \omega^2=(1/2)mv_{_{0}}^2+(1/2)I \omega_{_{0}}^2\)

Given Substitutions:

\(\omega=v/R\\\\ \omega_{_{0}}=v_{_{0}}/R\\\\\ I=(2/5)mR^2\)\(\hrulefill\)

Start by substituting in the appropriate values: \(mgh+(1/2)mv^2+(1/2)I \omega^2=(1/2)mv_{_{0}}^2+(1/2)I \omega_{_{0}}^2 \\\\\\\\\Longrightarrow mgh+(1/2)mv^2+(1/2)\bold{[(2/5)mR^2]} \bold{[v/R]}^2=(1/2)mv_{_{0}}^2+(1/2)\bold{[(2/5)mR^2]}\bold{[v_{_{0}}/R]}^2\)

Adjusting the equation so it easier to work with.\(\Longrightarrow mgh+\dfrac{1}{2} mv^2+\dfrac{1}{2} \Big[\dfrac{2}{5} mR^2\Big]\Big[\dfrac{v}{R} \Big]^2=\dfrac12mv_{_{0}}^2+\dfrac12\Big[\dfrac25mR^2\Big]\Big[\dfrac{v_{_{0}}}{R}\Big]^2\)

\(\hrulefill\)

Simplifying the left-hand side of the equation:

\(mgh+\dfrac{1}{2} mv^2+\dfrac{1}{2} \Big[\dfrac{2}{5} mR^2\Big]\Big[\dfrac{v}{R} \Big]^2\)

Simplifying the third term.

\(\Longrightarrow mgh+\dfrac{1}{2} mv^2+\dfrac{1}{2} \Big[\dfrac{2}{5} mR^2\Big]\Big[\dfrac{v}{R} \Big]^2\\\\\\\\\Longrightarrow mgh+\dfrac{1}{2} mv^2+\dfrac{1}{2}\cdot \dfrac{2}{5} \Big[mR^2\Big]\Big[\dfrac{v}{R} \Big]^2\\\\\\\\\Longrightarrow mgh+\dfrac{1}{2} mv^2+\dfrac{1}{5} \Big[mR^2\Big]\Big[\dfrac{v}{R} \Big]^2\)

\(\\ \boxed{\left\begin{array}{ccc}\text{\Underline{Power of a Fraction Rule:}}\\\\\Big(\dfrac{a}{b}\Big)^2=\dfrac{a^2}{b^2} \end{array}\right }\)

\(\Longrightarrow mgh+\dfrac{1}{2} mv^2+\dfrac{1}{5} \Big[mR^2\Big]\Big[\dfrac{v^2}{R^2} \Big]\\\\\\\\\Longrightarrow mgh+\dfrac{1}{2} mv^2+\dfrac{1}{5} \Big[mR^2 \cdot\dfrac{v^2}{R^2} \Big]\)

"R²'s" cancel, we are left with:

\(\Longrightarrow mgh+\dfrac{1}{2} mv^2+\dfrac{1}{5} \Big[mR^2\Big]\Big[\dfrac{v^2}{R^2} \Big]\\\\\\\\\Longrightarrow mgh+\dfrac{1}{2} mv^2+\dfrac{1}{5}mv^2\)

We have like terms, combine them.

\(\Longrightarrow mgh+\dfrac{1}{2} mv^2+\dfrac{1}{5} \Big[mR^2\Big]\Big[\dfrac{v^2}{R^2} \Big]\\\\\\\\\Longrightarrow mgh+\dfrac{7}{10} mv^2\)

Each term has an "m" in common, factor it out.

\(\Longrightarrow m(gh+\dfrac{7}{10}v^2)\)

Now we have the following equation:

\(\Longrightarrow m(gh+\dfrac{7}{10}v^2)=\dfrac12mv_{_{0}}^2+\dfrac12\Big[\dfrac25mR^2\Big]\Big[\dfrac{v_{_{0}}}{R}\Big]^2\)

\(\hrulefill\)

Simplifying the right-hand side of the equation:

\(\Longrightarrow \dfrac12mv_{_{0}}^2+\dfrac12\cdot\dfrac25\Big[mR^2\Big]\Big[\dfrac{v_{_{0}}}{R}\Big]^2\\\\\\\\\Longrightarrow \dfrac12mv_{_{0}}^2+\dfrac15\Big[mR^2\Big]\Big[\dfrac{v_{_{0}}}{R}\Big]^2\\\\\\\\\Longrightarrow \dfrac12mv_{_{0}}^2+\dfrac15\Big[mR^2\Big]\Big[\dfrac{v_{_{0}}^2}{R^2}\Big]\\\\\\\\\Longrightarrow \dfrac12mv_{_{0}}^2+\dfrac15\Big[mR^2\cdot\dfrac{v_{_{0}}^2}{R^2}\Big]\\\\\\\\\Longrightarrow \dfrac12mv_{_{0}}^2+\dfrac15mv_{_{0}}^2\Big\\\\\\\\\)

\(\Longrightarrow \dfrac{7}{10}mv_{_{0}}^2\)

Now we have the equation:

\(\Longrightarrow m(gh+\dfrac{7}{10}v^2)=\dfrac{7}{10}mv_{_{0}}^2\)

\(\hrulefill\)

Now solving the equation for the variable "v":

\(m(gh+\dfrac{7}{10}v^2)=\dfrac{7}{10}mv_{_{0}}^2\)

Dividing each side by "m," this will cancel the "m" variable on each side.

\(\Longrightarrow gh+\dfrac{7}{10}v^2=\dfrac{7}{10}v_{_{0}}^2\)

Subtract the term "gh" from either side of the equation.

\(\Longrightarrow \dfrac{7}{10}v^2=\dfrac{7}{10}v_{_{0}}^2-gh\)

Multiply each side of the equation by "10/7."

\(\Longrightarrow v^2=\dfrac{10}{7}\cdot\dfrac{7}{10}v_{_{0}}^2-\dfrac{10}{7}gh\\\\\\\\\Longrightarrow v^2=v_{_{0}}^2-\dfrac{10}{7}gh\)

Now squaring both sides.

\(\Longrightarrow \boxed{\boxed{v=\sqrt{v_{_{0}}^2-\dfrac{10}{7}gh}}}\)

Thus, the simplified equation above matches the simplified equation that was given.  

(a) The mass of water is approximately 49.65 kg. (b) The final temperature of the water vapor will be 120°C. (c) The total enthalpy change is approximately 277,956 kJ. (d) Diagram shown below.

(a) To determine the mass of the water, we need to know its density at the given conditions. The density of water changes with temperature and pressure. At 40°C and 200 kPa, the density of water is approximately 993 kg/m³.

Since we have 50 L of water, we need to convert it to cubic meters:

50 L = 0.05 m³

Now we can calculate the mass of water:

Mass = Density * Volume

Mass = 993 kg/m³ * 0.05 m³

Mass ≈ 49.65 kg

Therefore, the mass of water is approximately 49.65 kg.

(b) To find the final temperature, we need to consider the phase change from liquid to vapor. At constant pressure, the temperature will remain constant until all the liquid water has vaporized. This temperature is called the saturation temperature.

We can determine the saturation temperature at 200 kPa using a steam table or other relevant data sources. Let's assume that the saturation temperature is 120°C.

Therefore, the final temperature of the water vapor will be 120°C.

(c) To calculate the total enthalpy change, we need to consider the energy required to heat the water from its initial temperature to the saturation temperature, as well as the energy required for the phase change from liquid to vapor.

The enthalpy change during heating can be calculated using the formula:

ΔH1 = Mass * Specific Heat Capacity * ΔT1

Where:

Mass = 49.65 kg (from part a)

Specific Heat Capacity = specific heat capacity of water at constant pressure = 4.18 kJ/(kg·°C)

ΔT1 = final temperature - initial temperature = 120°C - 40°C = 80°C

ΔH1 = 49.65 kg * 4.18 kJ/(kg·°C) * 80°C

ΔH1 ≈ 165,938 kJ

The enthalpy change during phase change can be calculated using the formula:

ΔH2 = Mass * Latent Heat of Vaporization

Where:

Mass = 49.65 kg (from part a)

Latent Heat of Vaporization = energy required to vaporize 1 kg of water = 2257 kJ/kg

ΔH2 = 49.65 kg * 2257 kJ/kg

ΔH2 ≈ 112,018 kJ

The total enthalpy change is the sum of ΔH1 and ΔH2:

Total Enthalpy Change = ΔH1 + ΔH2

Total Enthalpy Change ≈ 165,938 kJ + 112,018 kJ

Total Enthalpy Change ≈ 277,956 kJ

Therefore, the total enthalpy change is approximately 277,956 kJ.

(d) The process can be shown on a T-v (temperature-volume) diagram with respect to saturation lines. In this case, the process starts at the initial temperature and pressure (40°C, 200 kPa), and moves along the constant pressure line until reaching the saturation temperature (120°C). Then, the process follows the saturation line until the entire liquid is vaporized.

Here is a simplified representation of the process on a T-v diagram:

           |

Saturation |                       |

 Line   |                             |

           |                             |

           |                             |

           |                             |

           |                             |

           |                             |

           |                             |

 Initial |-----------------------------| Final

           |                             |

           |                             |

           |                             |

           |                             |

           |                             |

           |                            

This diagram is a rough representation and does not accurately reflect specific volume values or scale. It simply illustrates the general process from initial conditions to the final state along the constant pressure and saturation lines.

for more such questions on enthalpy  

https://brainly.com/question/30654988

#SPJ11

Answer:

the boy would go missing

Answer: Slender man converts the boy to christianity

Answer:

scarcer

Explanation:

Silver is more costly than iron because it is scarcer as it is found only in some areas of the country... it's a rare element hence it is scarcer and more expensive..

Answer:

\(a=4.8m/s^2\)

Explanation:

Hello,

In this case, since the acceleration in terms of position is defined as its second derivative:

\(a=\frac{d^2x(t)}{dt^2}=\frac{d^2}{dt^2}(2.9+8.8t+2.4t^2)\)

The purpose here is derive x(t) twice as follows:

\(a=\frac{d^2x(t)}{dt^2}=\frac{d}{dt}(8.8+2*2.4*t)\\ \\a=4.8m/s^2\)

Thus, the acceleration turns out 4.8 meters per squared seconds.

Best regards.

Answer:

it is light

Explanation:

the arrow that says light is on the glass it must be near from tungsten

The device I would design to minimize impact from a collision would be a shock absorber made from a combination of rubber and metal. The device would be installed between the two colliding objects, and its function would be to absorb and dissipate the energy of the collision, thereby reducing the impact forces on the objects.
CONSTRUCTION:

Compared to existing shock-absorbing devices such as airbags and crumple zones, this design would be more efficient in reducing the impact forces on the colliding objects. Unlike airbags and crumple zones, which are designed to absorb the impact forces by deforming, the shock absorber would absorb the impact energy through compression and dissipation of the energy as heat.

Compared to existing devices such as generators and batteries, the piezoelectric generator would be more efficient in converting mechanical energy into electrical energy. This is because the piezoelectric effect is a direct conversion of mechanical energy into electrical energy, without the need for any intermediate steps such as the conversion of mechanical energy into rotational energy in a generator. Additionally, the piezoelectric generator would be smaller and more lightweight than traditional generators, making it ideal for use in portable electronic devices.

Answer:

the rate at which his body is losing heat by conduction is 93.6 J/s

Explanation:

Given that;

surface area A = 1.8 m²

Skin temperature of the person Tp = 32°C = ( 34 + 273.15 ) = 307.15 K

Temperature of Air \(T_{air}\) = 24°C = ( 24 + 273.15 ) = 297.15 K

Temperature of wall \(T_{wall}\) = 17°C = ( 17 + 273.15 ) = 290.15 K

Length ( thick dead layer = 5 mm = 0.005 m

Skin emissivity = 0.97

Rate of metabolism = 155 W

rate his body is losing heat by conduction = ?

first we determine the difference in temperature between the skin and air

so

ΔT = 307.15 K - 297.15 K = 10 K

we know that; coefficient of thermal heat conductivity of air k = 0.026 W/mK

so

rate of heat loss by conduction Q/ΔT will be;

Q/ΔT = (KA/L)ΔT

so we substitute

= ( 0.026 × 1.8/ 0.005 )10

= 9.36 × 10

= 93.6 J/s

Therefore, the rate at which his body is losing heat by conduction is 93.6 J/s

Answer:

Explanation:

Let R5 be the resistance between R3 and R4

R3 and R4 are in series

R5=R3+R4 = 9+8=17

R1, R2 and R5 are in parallel

Resistance R between A and B is :

1/R= 1/R1+1/R2+1/R5=1/7+1/10+1/17=170+119+70/1190=359/1190

1/R=359/1190

R=1190/359=3.314 Ω

Rounding to nearest hundredth we get 3.31Ω

Due to light refraction, any fish in the water can see a fisherman on the bank a little more clearly than one might anticipate. When the light hits the water's surface, it “bends” down by around 13 degrees, leaving the image. Thus option A is correct.

When it reaches the surface, light emanating from the fish refracts (changes direction). When viewed from above the water, a fish appears to be closer to the surface than it actually is.

Therefore, Fred the fisherman has been told that, because of refraction, a fish in water will appear.

Learn more about fisherman here:

https://brainly.com/question/10776600

#SPJ1

The AMA is the quotient between the input and output forces and is given by:

Where:

Therefore, the AMA is decreased if the input force is increased. If in a machine the friction force increases due to low maintenance then the required input force would increase and therefore, the AMA would decrease.

In a first-class lever we have the following:

We can calculate the ratio between input and output forces by adding the torque around the fulcrum:

Adding the product of the input force and input distance:

Now, we divide both sides by the input force:

Now, we divide both sides by the output distance:

Therefore, the AMA is:

Therefore, if in the lever we increase the input distance or decrease the output distance we would increase the AMA.