Marina walked 2km in half an hour, what was her average speed during her walk?

Answers

Answer 1

Answer:

4km/hr

Explanation:


Related Questions

What is the mass of the object if it exerted a
force of 62.2 Newtons and has an acceleration
of 15.3 m/s2?

Answers

Answer:

The object has an approximate mass of 4.06 kilograms.

Explanation:

Force is equal to mass times acceleration, so all we need to do is divide the force provided by the acceleration provided.

[tex]m = \frac{62.2N}{15.3 \frac{m}{s^2}}\\\\m = \frac{62.3kg\frac{m}{s^2}}{15.3 \frac{m}{s^2}}\\\\m = \frac{62.2kg}{15.3}\\\\m = 4.06kg[/tex]

Jeff throws a ball straight up. For which situation is the vertical velocity zero?
a. on the way up
b. at the top
c. on the way back down
d. none of the above

Answers

Answer:

b. at the top

Explanation:

At the top of the climb, the vertical velocity of Jeff's throw has a value of zero.

Vertical velocity in this instance is acting against the acceleration due to gravity.

At the top of the thrown, the force of the throw becomes zero and the velocity also becomes zero. As the body finds it way downward, it begins to fall freely. The fall is due to the acceleration due to gravity which is experienced by every object on earth.

what is the kinetic energy of a 0.25kg ball rolling at a speed of 2.5m/s

Answers

Answer:

Explanation:

Kinetic Energy formula:

KE = [tex]\frac{1}{2}[/tex]mv²

m=mass

v=speed

Given:

m=0.25kg

v=2.5m/s

Plug the values in:

KE = 1/2(0.25kg)(2.5m/s)²

KE = 0.78125 J (Joules)

Which statement explains what happened next? Positive feedback caused his pancreas to stop secreting insulin. Negative feedback caused his pancreas to stop secreting insulin. Negative feedback caused his pancreas to produce more insulin. Positive feedback caused his pancreas to produce more insulin.

Answers

Answer:

Negative feedback caused his pancreas to produce more insulin.

Explanation:

Positive feedback is a feedback that causes an increase of product as a result of change while negative feedback is a feedback that causes a decrease in product as a result.

Negative feedback mechanism can be shown in the body as the control of blood sugar. The blood sugar is the product to be controlled. When there is an increase in blood sugar, the nerves sense a change. This change leads to secretion of insulin by the pancreas until homeostasis and then the secretion stops.

Answer:

negative feedback cause his pancreas to stop secreting insulin.

Explanation:

What is the potential energy of a 5.0 N weight that is 3 m above the ground

Answers

Answer:

[tex]15\:\mathrm{J}[/tex]

Explanation:

The potential energy of an object is given by [tex]PE=mgh[/tex].

Recall that the weight of an object is equal to the force of gravity on the object. From this, we can set up the following equation and solve for the mass of the object:

[tex]F=mg,\\5=mg,\\m=\frac{5}{9.81}\approx 0.51\:\mathrm{kg}[/tex]

Now we can plug in values to [tex]PE=mgh[/tex] and solve:

[tex]PE=0.51\cdot9.81\cdot3=\fbox{$15\:\mathrm{J}$}[/tex].

Answer:

The potential energy of the body is 15J.

Explanation:

What is potential energy?

The energy possessed to a body due to position is called Potential energy.

U=mgh

Given data:weight (mg)=5Nheight (h)=3mPotential energy (U)=?by using formula

U=mgh

U=5×3=15J

Hence, the potential energy of the body is 15J.

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A car battery provides a voltage of 12 V to a vehicle. If 32 A of
current are drawn on a hot summer evening when the air conditioning
and lights are running, what is the resistance provided by the
electrical elements of the car?
A. 44 Ohms
B. 20 Ohms
C. 2.6 Ohms
D. 0.375 Ohms

Answers

Answer:

The resistance provided by the electrical elements is;

D. 0.375 Ohms

Explanation:

The relationship between the voltage, V, current, I, and resistance, R of an electric circuit is given as follows;

V = I × R

The given parameters of the circuit are;

The voltage provided by the car battery, V = 12 V

The current drawn by the air conditioning and lights, I = 32 A

From, V = I × R, we have;

R = V/I

Therefore, by substituting the known values, we have;

R = 12 V/(32 A) = 0.375 Ohms

The resistance provided by the electrical elements, R = 0.375 Ohms

what are 3 physical changes of plastic

Answers

Answer:

1. Size

2. Shape

3. Color

Explanation:

Sorry if this is no help

The muscle cells of an elephant Zontain 62 chromosomes. How many
chromosomes are in an elephant egg cell?

Answers

There are about 31 chromosomes in an elephant egg cell

Answer:

31

Explanation:

In meiosis each sex cell has half the half the number of chromosomes than the parent cell. 62/2=31

How does your brain know which direction a sound comes from ?

Answers

Answer:

Your brain is able to do this by comparing tiny differences in the way that sounds affect each ear. ... Signals from the ear travel along the auditory nerve to the brainstem, where each individual cell responds to a specific time difference and direction.

Explanation:

It's because of your ears.

"Energy is never created of destroyed, it only transforms from one form to another" is the definition of… A. The Law of Diminishing Returns B. The Law of Conservation of Energy C. The Law of Universal Gravitation D. The Law of Entropy

Answers

Answer:

B. The Law of Conservation of Energy

Explanation:

In Science, energy can be defined as the ability of an object or body to do work. There are two (2) main types of energy and these are;

I. Kinetic energy: it can be defined as an energy possessed by an object or body due to its motion.

Mathematically, kinetic energy is given by the formula;

Where, K.E represents kinetic energy measured in Joules.

M represents mass measured in kilograms.

V represents velocity measured in metres per seconds square.

II. Potential energy: it can be defined as an energy possessed by an object or body due to its position.

Mathematically, potential energy is given by the formula;

Where, P.E represents potential energy measured in Joules.

m represents the mass of an object.

g represents acceleration due to gravity measured in meters per seconds square.

h represents the height measured in meters.

Additionally, the various forms of energy are solar energy, electrical energy, chemical energy, thermal energy, wind energy, nuclear energy etc.

Hence, energy is never created of destroyed, it only transforms from one form to another" is the definition of The Law of Conservation of Energy.

At the time of the founding of the country, most Americans worked as
A.shopkeepers
B.soldiers
C.ship builders
D.farm workers

Answers

Answer:

Farmers

Explanation:

At the time of founding our country most soldiers in the revolutionary war were farmers who were inexperienced.

Answer:

D. farm workers

Explanation:

It is because when they started founding the country, people needed food and everything was based on agriculture and economy, and the main economy wat cotton and tobacco.

Read each of the phrases below. Put the phrases in the correct order to show the path of blood flow in the circulatory system starting with the blood traveling from the lungs.
___ blood picks up waste products such as carbon dioxide
___ carries oxygen and nutrients to the body cells
____ moves to right ventricle and to lungs
____ blood travels from the lungs to the left atrium
____ returns to right atrium

Answers

Answer:

__3__ blood picks up waste products such as carbon dioxide

__2__ carries oxygen and nutrients to the body cell

__1__ moves to right ventricle and to lungs

__4__ blood travels from the lungs to the left atrium

__5__ returns to right atrium

Explanation:

PLS MARK BRAINLEST

Both vena cava passes the deoxygenated blood to the right atrium. Blood from right atrium enters right ventricle and pulmonary arteries carry deoxygenated blood from right ventricle to lungs for oxygenation. Two pulmonary veins come from each lung and pass O2 -rich blood to left atrium. Blood enters left ventricle from the left atrium. The left ventricle pumps blood into the aorta which in turn branches and delivers blood to the major body regions and organs.

How much energy is required to completely boil away 225 kg of water?
Hv = 226,000 J/kg
Hf = 334,000 J/kg

Answers

Answer:

E = 50850[kJ]

Explanation:

To boil the water we must use the latent heat of vaporization. Also we need to multiply this value by the mass of the water.

[tex]E=m*H_{v}[/tex]

Where:

E = energy produced by heat [J]

m = mass = 225 [kg]

Hv = 226000 [J/kg]

[tex]E = 225*226000\\E = 50850000 [J]\\E=50850[kJ][/tex]

14. A television has a cash price of $1299. It can be purchased on a Hire Purchase plan by
making a deposit of $500 plus 10 monthly payments of $95. What is the total monthly
installment.
a) S1450
b) S450
c) S1299
d) S950​

Answers

It's a)S1450
PLATO4LIFE I Took the test.

When one end of a metal bar is heated, the opposite end will eventually become hot. Which of the following processes transfers the heat through the bar?

Group of answer choices

condensation

radiation

convection

conduction

Answers

I believe it’s convection
Conduction is your answer. Conduction is the process in which the heated and the faster molecules collide with other molecules to transfer the heat from the hot end to the colder end.

Starting from rest, a sprinter reaches his top velocity in 3 seconds. He runs a distance of 24m in 3 seconds. What is his acceleration? (Assume his acceleration is uniform)

Answers

Answer:

[tex]a=5.34\ m/s^2[/tex]

Explanation:

Given that,

Initial velocity of a sprinter, u = 0

He runs a distance of 24m in 3 seconds.

We need to find his acceleration. Let a be his acceleration. Using second equation of kinematics to find it.

[tex]s=ut+\dfrac{1}{2}at^2\\\\24=0+\dfrac{1}{2}a(3)^2\\\\a=\dfrac{24\times 2}{9}\\\\a=5.34\ m/s^2[/tex]

So, the acceleration of the sprinter is [tex]5.34\ m/s^2[/tex].

The acceleration of the sprinter from rest to his top speed is 5.33m/s²,

Given the data in the question

Since the sprinter starts from rest,

Initial velocity; [tex]u = 0[/tex]Time taken; [tex]t = 3s[/tex]Distance covered; [tex]s = 24m[/tex]

Acceleration; [tex]a = \ ?[/tex]

To determine the acceleration of the sprinter, we use the second equation of motion:

[tex]s = ut + \frac{1}{2}at^2[/tex]

Where s is distance covered, u is initial velocity, a is acceleration and t is time.

We substitute our given values into the equation

[tex]24m = [0 * 3s] + [\frac{1}{2} * a * (3s)^2]\\\\24m = \frac{1}{2} * a * 9s^2\\\\24m = a * 4.5s^2\\\\a = \frac{24m}{4.5s^2} \\\\a = 5.33m/s^2[/tex]

Therefore, the acceleration of the sprinter from rest to his top speed is 5.33m/s²

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Derive Isothermal process through ideal gas.(anyone plzz!!)​

Answers

Answer:

Hey, bro here is the explanation....

Explanation:

Hope it helps...

A simple pendulum has a period of 3.45 seconds. When the length of the pendulum is shortened by 1.0m,the period is 2.81 seconds, calculate (a) the original length of the pendulum (b) The value of acceleration due to gravity

Answers

Answer:

2.97 meters

9.85 m/s^2

Explanation:

Given that :

Period (T1) = 3.45 seconds

When length , l is shortened by 1m, period (T2) = 2.81 seconds

Using the relation :

T = 2π√l/g

g = acceleration due to gravity

T1 = 2π√L/g - - - - (1)

Period 2:

x = shortened length = 1m

T2 = 2π√L-x/g - - - (2)

Square both sides

T1² = (2π)² L/g - - - (3)

T2² = (2π)² L-x/g - - (4)

Divide 3 and 4

(T2/T1)² = (L-x) / L

(2.81/3.45)^2 = (L - 1) / L

0.6633984 = (L - 1) / L

0.6633984L = L - 1

0.6633984L - L = - 1

−0.336601L = - 1

L = 1 / 0.336601

L = 2.9708764

Length = 2.97 meters

Acceleration due to gravity :

g = L(2π/T1)^2

g = 2.97(2π / 3.45)^2

g = 2.97 * 3.3168172

g = 9.8509

g = 9.85 m/s^2

g


Help me to solve this please

Answers

Answer:

2) 7

3) 5

Explanation:

Answer:

the are are7

D

Explanation:

PLEASE HELP NOT A LOT OF TIME LEFT!!!!!
A vector is drawn on an x-y plane. It has a magnitude of 65.1 centimeters and a direction of 28.0 degrees below the positive x-axis. What is the x-component of this vector?

A. 30.6cm
B. 65.1cm
C. 27.1cm
D. 57.5cm

Answers

The [x] component will be +57.47 a[x]  and the [y] component will be -30.51 a[y].

What are the components of a vector?

Any vector can be resolved along the axes of the cartesian coordinate system. For a two dimensional vector (say [V]), it can be resolved along the

[x] and [y] axis, such that the components of the vector are the vector's themselves and are given by -

[x] component = VcosФ a[x]

[y] component = VsinФ a[y]

Given is a vector is drawn on an X - Y plane. It has a magnitude of 65.1 centimeters and a direction of 28.0 degrees below the positive x-axis.

From the data given, we can write -

Magnitude of vector = |V| = 65.1

Angle made with +x axis = [Ф] =28 degrees {below the axis}

Therefore, the [x] component will be -

[x] = 65.1 x cos(28) = 57.47 a[x]

and the [y] component will be -

[y] = 65.1 x sin(28) = 30.51 × -a[y] = -30.51 a[y]

Therefore, the [x] component will be +57.47 a[x]  and the [y] component will be -30.51 a[y].

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Which of these would be the most efficient means to transmit light pulses over long distances?

Answers

Answer: It’s fiber optics so B

A student is leaving the lesson and walking to Maths at a speed of 1m/s. He notices that he is late for the lesson and speeds up to 3 m/s. It takes him 4 seconds to speed up. Calculate his acceleration.

Answers

Answer:

Acceleration = 0.5 m/s²

Explanation:

Given the following data;

Initial velocity, u = 1m/s

Final velocity, v = 3m/s

Time, t = 4 seconds

To find acceleration;

In physics, acceleration can be defined as the rate of change of the velocity of an object with respect to time.

This simply means that, acceleration is given by the subtraction of initial velocity from the final velocity all over time.

Hence, if we subtract the initial velocity from the final velocity and divide that by the time, we can calculate an object’s acceleration.

Mathematically, acceleration is given by the equation;

[tex]Acceleration (a) = \frac{final \; velocity - initial \; velocity}{time}[/tex]

[tex]a = \frac{v - u}{t}[/tex]

Substituting into the equation, we have;

Acceleration = (3 - 1)/4

Acceleration = 2/4

Acceleration = 0.5 m/s²

what is the diffference between distance and displacement

Answers

Answer:

distance is how far away something has travelled from another object, while displacement is how far something is from the other object. Displacement is a vector quantity, unlike distance.

why is the index of refraction important for achromatic lenses?

Answers

Answer:

Refractive index is a measure of how light propagates through a material. The higher the refractive index the slower the light travels, which causes a correspondingly increased change in the direction of the light within the material.

Explanation:

A 2-kg ball traveling eastward at 5 m/s hits a 5-kg ball moving at 1 m/s eastward. The 2-kg ball bounces west at 3.0 m/s. What is the speed of the 5kg ball?

Answers

Answer:

1.8 m/s

Explanation:

Step one:

given data

m1= 2kg

u1= 5m/s

m2= 5kg

u2= 1m/s

v1= 3m/s

From

m1u1+m2u2= m1v1+m2v2

substitute

2*5+5*1 = 2*3+5*v2

10+5= 6+5v2

15-6= 5v2

9= 5v2

divide both side by 5

v2= 9/5

v2= 1.8 m/s



(b)Suggest with reasons,what must be added to the flask to keep the liquid hot.
____________________________________________________​​

Answers

(a) a thin layer of vacuum is provided between the two walls of flask, to minimise the heat loss by conduction , because for conduction medium (molecules) is required , but now medium is absent .

.(b) the two walls are silvered to minimise the heat loss by radiation , because a shiny surface is a bad absorber and bad emitter of radiation i.e. good reflector of heat , so prevents the heat exchange between content of flask and surrounding .

(c) the lid of flask is provided with a tight cork stopper to minimise the heat loss by convection , so that convection currents cannot go out .

(d) a plastic (or metal) case is provided with a flask , to protect the flask from physical damage

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I really need your help, please help me. How do I solve for ke without even having mass

Answers

I’m not fully sure - I’m studying the same topic as you in school and we haven’t covered it yet. BUT I can help you a teeny bit....

Note: You May know this but velocity means speed.

The formula for calculating kinetic energy is :

Ek = 1/2 mv2

E= kinetic energy ( J )
M= mass (kg)
V = velocity (m/s)

If you want to calculate the acceleration of a car, you should _____ the change in velocity of the car by the time interval.
A. Multiply
B. Increase
C. Divide
D. Decrease

Answers

Answer:

Your awnser is B. Increase

Explanation:

Answer:

divide

Explanation:

u should divide the velocity by time interval because a=vf-vi/t

100 points!!!! Will mark brainliest!!!!!!!!



This child is in motion jumping on a trampoline. There are four forces that apply to this situation. Which are they?

Applied force
Normal force
Tension force
Friction force
Spring force
Air-Resistance force
Electrical force
Magnetic force
Gravitational force

Answers

Answer:

Normal Force, Applied force, Gravitational Force, Spring Force

Explanation:

Normal Force so that he does not fall into trampoline, spring because the trampoline spring down when the force goes down, then up putting force upwards, gravitation because of gravity, and applied because of jumping

Answer:

i told u my thing got deleted lol

Explanation:

A jet aircraft is traveling at 262 m/s in horizontal flight. The engine takes in air at a rate of 85.9 kg/s and burns fuel at a rate of 3.92 kg/s. The exhaust gases are ejected at 921 m/s relative to the aircraft. Find the thrust of the jet engine. Answer in units of N Find the delivered power. Answer in units of W.

Answers

Answer:

[tex]F_T=60132.52N[/tex]

[tex]P=15814852.76W[/tex]

Explanation:

From the question we are told that

Velocity of aircraft  [tex]V=263m/s[/tex]

Engine air intake rate [tex]\triangle M_a=85.9kg/s[/tex]

Fuel burn rate  [tex]\triangle M_f =3.92kg/s[/tex]

Velocity of exhaust gas [tex]V_e =921m/s[/tex]

Generally the Mass change rate of Rocket is mathematically given by

 [tex]\triangle M = \triangle M_a+\triangle M_f[/tex]

 [tex]\triangle M= 85.9+3.92[/tex]

 [tex]\triangle M=89.82kg/s[/tex]

Generally the Trust of the rocket is given mathematically by

 [tex]F_T=(\triangle M *V_e)-(dM_a/dt)*(V)[/tex]

 [tex]F_T=(89.82 *921)-(85.9)*(263)[/tex]

 [tex]F_T=60132.52N[/tex]

Generally the Rocket's delivered power is mathematically given by

Delivered power P

 [tex]P=V*F_T[/tex]

 [tex]P=263*60132.52N[/tex]

 [tex]P=15814852.76W.[/tex]

Other Questions
Match each expression on the left with an equivalent expression on the right. Some answer choices on the right will not be used. Gregs cocker spaniel weighs 32 pounds. His kitten weighs 15 ounces. What does this quotation mean to you? Why do you think the author wrote this quotation? Be sure to use specific examples or textual evidence from research, the readings in this class, or your own experiences and knowledge. Prompt: Quotation 1: A sentence fromThe Book of Genesis, Chapter 6 Yahweh saw that the wickedness of man was great in the earth, and that every imagination of the thoughts of mans heart was continually only evil. Which of the following is the lysosome? Write an ordered pair for 3 glassesand the amount of juice needed.( PLEASE HURRYY !!) Althea paid $5.00 each for two bracelets and later sold each for $15.00. She paid $8.00 each for three braceletsand sold each of them for $9.00.a. Write an expression that represents the profit Althea made.b. Evaluate the expression. Name the property used in each step. what is 3 1/8 x 2 3/5 What is the mass of the object if it exerted aforce of 62.2 Newtons and has an accelerationof 15.3 m/s2? help me pleaseee pleaseee Pip has found that the life of a gentleman is not exactly what he expected. In chapter 31, Pip and Herbert go to see Mr. Wopsle's play -- an unintentionally hilarious performance of Shakespeare's Hamlet. What similarities can be drawn between Pip's situation and Mr. Wopsle's situation?Group of answer choicesWopsle is realizing his dream of being an actor; Pip is realizing his dream of being a gentleman.All of thesePip and Wopsle both made it to the "big city."Mr. Wopsle's dream is not as he imagined; Pip's dream is not as he envisioned. A car takes 4 hours to cover a distance, if it travels a speed of 40 mph. What should be it's speed to cover the same distance in 1.5 hours? Help asappppp ? Writing linear Equations? Which is a legal punishment that could occur if a person is found to be driving while under the influence of alcohol? Help As soon as possible !!! What would you argue is the most important person, event, or invention of the last 100 years? (1920-2020) Why? PLEASE HELPPPPITS EASY MY BRAIN JUST HURTS what are carnivarose The __________, whose name is an Arabic word meaning "shore" or "edge," borders the Sahara Desert.A.SerengetiB.OkovangoC.LimpopoD.Sahel Sharif stared a new job working 15 hours a week after how many weeks will he have worked a total of 75 hours ? on a coordinate plane, three of the four verticles are located at the points (0,0), (5,5) and (6,2). what is the area, in square units, of the rectangle?A.20B.[tex]10 \sqrt{5} [/tex]C.32D.[tex]20 \sqrt{5} [/tex]