What must be the reaction force when someone hits a tree with an axe?

Answer:

Explanation:

If the distance to the end of the road was 40 m, and she traveled back to where she started, she traveled a total distance of 80 m. It took her 100 seconds to travel the 80 m.

Based on the given distance-time graph, the number of seconds that Angela used to go to the end of the road and arrive back is 100 seconds.

The end of the road is 40m and coming back is also 40 m. The total distance is:

= 40 + 40

= 80m

The graph shows that to walk 80 meters, Angela took a 100 seconds because the line on the graph ends at 80 m and 100 seconds.

Find out more uses of distance-time graphs at https://brainly.com/question/13877898.

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Answer:

Explanation:

This is a recoil problem, which is just another application of the Law of Momentum Conservation. The equation for us is:

[tex][m_av_a+m_ev_e]_b=[m_av_a+m_ev_e]_a[/tex] which, in words, is

The momentum of the astronaut plus the momentum of the piece of equipment before the equipment is thrown has to be equal to the momentum of all that same stuff after the equipment is thrown. Filling in:

[tex][(90.0)(0)+(.50)(0)]_b=[(90.0)(v)+(.50)(-4.0)]_a[/tex]

Obviously, on the left side of the equation, nothing is moving so the whole left side equals 0. Doing the math on the right and paying specific attention to the sig fig's here (notice, I added a 0 after the 4 in the velocity value so our sig fig's are 2 instead of just 1. 1 is useless in most applications).

0 = 90.0v - 2.0 and

2.0 = 90.0v so

v = .022 m/s This is the rate at which he is moving TOWARDS the ship (negative was moving away from the ship, as indicated by the - in the problem). Now we can use the d = rt equation to find out how long this process will take him if he wants to reach his ship before he dies.

12 = .022t and

t = 550 seconds, which is the same thing as 9.2 minutes

Answer:

10 pa

Explanation:

4kg* 10 (or 9.8m/s2) = 40

40N /4m2 =10

The amount of solar radiation received by Earth from the sun, known as insolation, is greatest when the sun is directly overhead a location.

The amount of solar radiation received by Earth from the sun is known as insolation, solar insolation is greatest when the sun is directly overhead a location.

The energy transferred from the Sun in the form of electromagnetic radiation is known as the solar energy

It can be used as thermal energy for various life purposes as well as for electricity conversion with the help of solar photovoltaic cells

The ratio of total electrical energy generated by a solar photovoltaic panel to its total thermal energy is known as solar energy efficiency. The solar panel's area and design have an impact on how energy-efficient it is.

Thus, the term "insolation" refers to the amount of solar radiation that Earth receives from the sun. Solar insolation is highest when the sun is directly overhead a location.

Learn more about solar energy from here, refer to the link;

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Answer:

a. Magnetic field is a location of a vector field around an electric current or magnet formed due to moving electric charges, or magnetic material and has a magnetic effect and exerts a force on other magnetic materials, electric current, and electric charges. The Earth's magnetic field that has the effect of turning a compass needle is an example of a magnetic field

b. The number of turns of the coil, N, in Diagram 1.1 > The number of turns of the coil, N, in Diagram 1.2

The pattern of the iron filings in Diagram 1.1 are closer with less space in between than the pattern of iron filings in Diagram 1.2

The angle of deflection of the ammeter pointer in Diagram 1.1 will be > The angle of deflection of the ammeter pointer in Diagram 1.2, given that the number of turns and current are inversely proportional

c. i. The pattern of the iron filings will have rings which are more closely arranged to each other as the strength of the magnetic field is increased

ii. As the number of turns is increased, the magnetic field is increased

Explanation:

Answer:

Value of the resistors​ R = 2 ohm

Explanation:

Given:

Resistor R1 = 4 ohm

Resistor R2 = 4 ohm

Find:

Value of the resistors​ R

Computation:

We know that Resistor R1 and Resistor R2 connected in parallel series.

So,

Using common resistance in parallel series

⇒ 1/R = 1/R1 + 1/R2

⇒ 1/R = 1/4 + 1/4

⇒ 1/R = (1 + 1) / 4

⇒ 1/R = 2/4

⇒ R = 4/2

⇒ R = 2

Value of the resistors​ R = 2 ohm

Answer:

attached below

Explanation:

The initial conditions :

x(0) = - 9 inches = -3/4 ft

x'(0) = - 2 ft/sec

spring stretched  3 inches = 1/4 ft

mass = w / g = 4 Ib / 32 ft/sec^2 = 1/8  slug

the spring constant ( k ) = w / l  = 4 / ( 1/4 ) = 16 Ib/ft

applying the second law of motion

m d^2x/dt^2 +  b dx/dt  + kx

= 1/8 d^2x/dt^2  + 2 dx/dt  + 16 x

= d^2x/dt^2  + 16 dx/dt  +  128 x  ------- ( 1 )

we will resolve the above equation to obtain the required equation of motion  x( t )

Attached below is the remaining part of the solution

[tex]option \: (a) \: is \: correct.[/tex]

Explanation:

Yes, I was wrong. Pressure increases as the area decreases.

As per the Figure A, the truck is so heavy and having a greater mass. So, the area of contact between the tyres and the road increases and decreases it's pressure on the road due to the increase in area.

As per the Figure B, You know the nature of Tomato that it is soft and smooth to touch and also lighter mass when it's compared with the truck. As it having a lighter mass, it can be cut through the sharp knife. The area of contact decreases and pressure increases on the vegetables.

Answer:

Option number B

Explanation:

The pressure is indirectly proportional to the area therefore pressure decreases when the area increases, and pressure increases when the area decreases

Answer:

[tex] \rm 250000 \; cm^2 [/tex]

Explanation:

Refer to the attachment.

Answer:

[tex]Q=50.3[/tex]

Explanation:

From the question we are told that:

Frequency [tex]F=330Hz[/tex]

Sound intensity drop [tex]I_d=2[/tex]

Time [tex]T=4s[/tex]

Therefore

Sound intensity Ratio

 [tex]\frac{I}{I_x}=\frac{1}{2}[/tex]

Generally the equation for Sound intensity is mathematically given by

 [tex]\frac{I}{I_x}=e^{-4\ \=t}[/tex]

 [tex]\frac{1}{2}=e^{-4\ \=t}[/tex]

 [tex]\=t =5.8s[/tex]

Generally the equation for Quality Factor is mathematically given by

 [tex]Q=2 \pi\frac{E}{\triangle E}[/tex]

 [tex]Q=2 \pi\frac{E}{\frac{E}{2*4}}[/tex]

 [tex]Q=50.3[/tex]

Answer:

the force of resistance on the right team is 360 N

Explanation:

Given;

force of the left team, = 1000 N

total mass of the right team, m = 300 kg

acceleration of the right team, a = 1.2 m/s²

The force of resistance of the right team is calculated as;

Force = mass x acceleration

Force, F = 300 x 1.2

Force = 360 N

Therefore, the force of resistance on the right team is 360 N

Answer:

The law of momentum conservation can be stated as follows. For a collision occurring between object 1 and object 2 in an isolated system, the total momentum of the two objects before the collision is equal to the total momentum of the two objects after the collision.

Answer:

"the plants had already started growing."

Explanation:

I think this is the answer because the definition of a dependent variable is the variable that is being affected by the change. Since the plants had already started growing BECAUSE of "They ran out of the farmer's compost, so

some of the plants received that compost

when the seeds were planted and other

plants got hardware store compost after

the plants had already started growing."

Sorry if I am wrong, I am just a 4th grader, pls don't hate on me, I am just trying to help :)

Answer:

It's compost

Explanation:

In case you needed the dependent variable, its the amount of plant growth

Answer:

0.4

Explanation:

A concave lens is a diverging lens, so it will always have a negative focal length. Image distance is always negative for a concave lens because it forms virtual images.

From the lens formula;

1/f = 1/u+ 1/v

- 1/2 = 1/3 - 1/v

1/v = 1/3 + 1/2

v= 6/5

v= 1.2 cm

Magnification = image distance/object distance

Magnification = 1.2cm/3cm

Magnification = 0.4

Answer:

C. Increase in back emf

Explanation:

As the current through the field winding decreases the field strength also decreases and the back-emf is reduced, as a result the motor speeds up.

When the motor begins to speed-up, an additional back EMF is generated due to induction which reduces armature current. This also results in reduced strength of the field flux. The back emf generated is not enough to reduce the armature current which could stop the acceleration of the motor and the motor further accelerates.

Answer:

i) a₁ = -g (sin θ + μ cos θ), x = v₀² / 2a₁

ii) W = mg L sin  θ ,  iii)     Wₙ = 0

iv)  W = - μ m g  L cos  θ x

Explanation:

With a drawing this exercise would be clearer, I understand that you have a block on a ramp and it is subjected to some force that makes it rise, for example the tension created by a descending block.

The movement is that when the system is released, the tension forces are greater than the friction and the component of the weight and therefore the block rises up the ramp

At some point the tension must become zero, when the hanging block reaches the ground, as the block has a velocity it rises with a negative acceleration to a point and stops where the friction force and the weight component would be in equilibrium along the way. along the plane

i) Let's use Newton's second law

the reference system is with the x axis parallel to the ramp

Axis y

      N - W cos θ = 0

X axis

      T - W sin θ - fr = ma

the friction force is

      fr = μ N

      fr = μ mg cos θ

we substitute

      T - m g sin sin θ - μ mg cos θ = m a

      a = T / m - g (sin θ + μ cos θ)

With this acceleration we can find the height that the block reaches, this implies that at some point the tension becomes zero, possibly when a hanging block reaches the floor.

      T = 0

       a₁ = -g (sin θ + μ cos θ)

       v² = v₀² - 2a1 x

       v = 0       at the highest point

       x = v₀² / 2a₁

ii) the work of the gravitational force is

       W = F .d

       W = mg sin  θ   L

iii) the work of the normal force

the force has 90º with respect to the displacement so cos 90 = 0

         Wₙ = 0

iv) friction force work

friction force always opposes displacement

         W = - fr d

         W = - μ m g cos  θ L

Answer:

[tex]f = m \frac{v1 - v2}{t} \\ = 120 \times \frac{25 - 5}{2} \\ = 120 \times \frac{20}{2} \\ = 120 \times 10 \\ = 1200N \\ thank \: you[/tex]

Answer:

heuristic.

Explanation:

Psychology can be defined as the scientific study of both the consciousness and unconsciousness of the human mind such as feelings, emotions and thoughts, so as to understand how it functions and affect human behaviors in contextual terms.

This ultimately implies that, psychology focuses on studying behaviors and the mind that controls it.

A heuristic is an automatic mental shortcut or rule of thumb that avail people the opportunity to make quick and efficient judgement in decision-making process, as well as proffering solutions to a problem. Thus, it allows people to make decisions, pass probability judgement or proffer solutions to problem quickly and efficiently while applying minimal mental effort.

Basically, a heuristic helps an individual to shorten the decision-making time while paying less attention on thinking of his or her next course of action.

Hence, when you're advised to try working backward from the desired goal to the starting point or current state. This advice describes a heuristic.

Answer:

F2 = 900 lbs

Explanation:

From pascal principle;

F1/A1 = F2/A2

Force on cylinder at left; F1 = 100 lbs

Diameter of cylinder at left; d1 = 2 inches

Diameter of cylinder at right; d2 = 6 inches

Formula for area of top of cylinder = πr²

Thus;

Area of top of left cylinder; A = π × 2² = 4π

Area of top of right cylinder; A = π × 6² = 36π

Thus;

100/4π = F2/36π

F2 = (36π × 100)/4π

F2 = 900 lbs

Answer:

The correct option is a) 10 mph, 0 mph.

Explanation:

1. The average speed (S) is a magnitude given by:

[tex] S = \frac{D}{T} [/tex]  

Where:

D: is the total distance = 1 mi

T: is the total time = 6 min

[tex] S = \frac{D}{T} = \frac{1 mi}{6 min}*\frac{60 min}{1 h} = 10 mph [/tex]

Hence, the average speed is 10 mph.

2. The average velocity is a vector:

[tex] V = \frac{\Delta d}{\Delta t} = \frac{d_{f} - d_{i}}{t_{f} - t_{i}} [/tex]

Where:

[tex]d_{f}[/tex]: is the final distance                                    

[tex]d_{i}[/tex]: is the initial distance  

[tex]t_{f}[/tex]: is the final time                

[tex]t_{i}[/tex]: is the initial time

Since Juanita ran one mile around her school track, the final position is the same that the initial position, so the magnitude of the average velocity is zero.                                               

Therefore, the correct option is a) 10 mph, 0 mph.

I hope it helps you!          

Answer:

[tex]T=7.5*10^{-5}[/tex]

Explanation:

From the question we are told that:

Radius [tex]r=2cm[/tex]

Work done [tex]W=1.5×10^-4 joules[/tex]

Generally the equation for Work done is mathematically given by

 [tex]W=T.dA[/tex]

Therefore

 [tex]T=\frac{W}{dr}[/tex]

 [tex]T=\frac{1.5*10^{-4}}{2}[/tex]

 [tex]T=7.5*10^{-5}[/tex]

Answer:

1.25 m

Explanation:

From the question given above, the following data were obtained:

Force ratio = 2.5

Distance of load from the fulcrum = 0.5 m

Distance of effort =.?

The distance of the effort from the fulcrum can be obtained as illustrated below:

Force ratio = Distance of effort / Distance of load

2.5 = Distance of effort / 0.5

Cross multiply

Distance of effort = 2.5 × 0.5

Distance of effort = 1.25 m

Therefore, the distance of the effort from the fulcrum is 1.25 m

Answer:200 Mpa

Explanation:

Given that diameter of cylinder = d = 1-25cm = 1.25 100 =0.0125m

Load or mass = m = Stress 0 = ? 2500kg

Solution: Formula N = F A

Area of Cross-section of cylinder = A=πr2 A = π(d/2) 2

= π(d2/4)

=(3.14)(0.0125)2/4

A = 1.226x10-4

F ・ mg = = F A 24500 2500 x 9.8 = 24500 N

1-226x10-4

1998 36 867.9

= 200 x 106 Pa

= 200 MPa

*Hope it helps you*

Good luck

Mass and volume are called physical quantities because they can be measured by using physical devices i.e. mass is measured by using beam balance and volume is measured by using metre scale .

Answer:

the tension of the rope is 34.95 N

Explanation:

Given;

length of the rope, L = 3 m

mass of the rope, m = 0.105 kg

frequency of the wave, f = 40 Hz

wavelength of the wave, λ = 0.79 m

Let the tension of the rope = T

The speed of the wave is given as;

[tex]v = f\lambda = \sqrt{\frac{T}{\mu} } \\\\where;\\\\\mu \ is \ mass \ per \ unit \ length\\\\\mu = \frac{0.105}{3} = 0.035 \ kg/m\\\\v = f\lambda = 40 \times 0.79 = 31.6 \ m/s\\\\v = \sqrt{\frac{T}{\mu} } \\\\v^2 = \frac{T}{\mu} \\\\T = v^2 \mu\\\\T = (31.6^2)(0.035)\\\\T = 34.95 \ N[/tex]

Therefore, the tension of the rope is 34.95 N

Answer:

1) Disolver azúcar en agua - Cambio químico - Es un caso de una solución en donde el solvente es el azúcar y el soluto es el agua.

2) Freir una chuleta - Cambio físico - Es un proceso de cocinado por un transferencia de calor y transferencia de masa.

3) Arrugar un papel - Cambio físico - Se aplica fuerzas externas para deformar el papel.

4) El proceso de la digestión - Cambio químico - Reducción de los alimentos a desechos y la absorción de nutrientes por el contacto con jugos gástricos o ambientes intestinales.

5) Secar la ropa al sol - Cambio físico - El secado es un fenómeno de transferencia de masa.

6) Congelar una paleta de agua - Cambio físico - Cambio del estado líquido al estado sólido por transferencia de calor.

7) Hacer un avión de papel - Cambio físico - Aplicación de fuerzas externas para plegar y doblar la hoja de papel.

8) Oxidación del cobre - Cambio químico - Proceso de corrosión por contacto con iones que se transportan en el ambiente.

9) Romper un lápiz - Cambio físico - Proceso de ruptura por esfuerzo normal a causa de un momento como consecuencia de una fuerza externa aplicada sobre el lápiz.

10) Prender fuegos artificiales - Cambio químico - Reacción química de reducción-oxidación.

11) Excavar un hoyo - Cambio físico - Remoción de tierra por trabajo físico.

12) Quemar basura - Cambio químico - Reacción de combustión.

Explanation:

A continuación, veremos que representa cada caso:

1) Disolver azúcar en agua - Cambio químico - Es un caso de una solución en donde el solvente es el azúcar y el soluto es el agua.

2) Freir una chuleta - Cambio físico - Es un proceso de cocinado por un transferencia de calor y transferencia de masa.

3) Arrugar un papel - Cambio físico - Se aplica fuerzas externas para deformar el papel.

4) El proceso de la digestión - Cambio químico - Reducción de los alimentos a desechos y la absorción de nutrientes por el contacto con jugos gástricos o ambientes intestinales.

5) Secar la ropa al sol - Cambio físico - El secado es un fenómeno de transferencia de masa.

6) Congelar una paleta de agua - Cambio físico - Cambio del estado líquido al estado sólido por transferencia de calor.

7) Hacer un avión de papel - Cambio físico - Aplicación de fuerzas externas para plegar y doblar la hoja de papel.

8) Oxidación del cobre - Cambio químico - Proceso de corrosión por contacto con iones que se transportan en el ambiente.

9) Romper un lápiz - Cambio físico - Proceso de ruptura por esfuerzo normal a causa de un momento como consecuencia de una fuerza externa aplicada sobre el lápiz.

10) Prender fuegos artificiales - Cambio químico - Reacción química de reducción-oxidación.

11) Excavar un hoyo - Cambio físico - Remoción de tierra por trabajo físico.

12) Quemar basura - Cambio químico - Reacción de combustión.

Answer: 2.43 s

Explanation:

Initial velocity is [tex]u=15.2\ m/s[/tex]

Final velocity [tex]v=23\ m/s[/tex]

Average acceleration is [tex]a_{avg}=3.2\ m/s[/tex]

Average acceleration is change in velocity in the given amount of time

[tex]\therefore a_{avg}=\dfrac{v-u}{t}\\\\\Rightarrow 3.2=\dfrac{23-15.2}{t}\\\\\Rightarrow t=\dfrac{7.8}{3.2}\\\\\Rightarrow t=2.43\ s[/tex]

Thus, 2.43 s is required to acquire that average acceleration with 23 m/s velocity .