A student practicing for a cross country meet runs 250 m in 30 s. What is the average speed

Answers

Answer 1

Answer:8.3m/sec 30 sec,

Explanation:

A student practicing for a track meet, ran 250 m in 30 sec. a. What was her average speed? 250 m = 8.3 m/sec 30 sec.


Related Questions

Which point on the standing wave is a node?

Answers

The point on the standing wave which is referred to as a node is point B and is denoted as option B.

What is Standing wave?

This is also called stationary wave and it is referred to as a combination of two waves moving in opposite directions, each having the same amplitude and frequency.

A node is referred to as a point along a standing wave where the wave has minimum amplitude which is therefore denoted as point B in the graph given below.

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Which statement best explains the difference between longitudinal and transverse waves?


A: Longitudinal waves have troughs, while transverse waves have crests.

B: Longitudinal waves transfer energy while transverse waves do not

C: Longitudinal waves produce energy, while transverse waves consume energy

D: Particles in longitudinal waves travel in the direction of the wave, while particles in transverse waves travel perpendicular to the wave.
pls put the letter in the answer

Answers

Answer:

the answer here would be A

The statement that best explains the difference between longitudinal and transverse waves is D: Particles in longitudinal waves travel in the direction of the wave, while particles in transverse waves travel perpendicular to the wave. The correct option is D.

What is a wave?

A wave is a disturbance that propagates through space and time, transferring energy without transferring matter. Waves can be found in various forms, such as sound waves, light waves, and water waves.

A transverse wave is a type of wave where the particles of the medium vibrate perpendicular to the direction of wave propagation.

In other words, the motion of the particles is at right angles to the direction of the energy transfer. A common example of transverse waves is light waves.

A longitudinal wave is a type of wave where the particles of the medium vibrate parallel to the direction of wave propagation. The motion of the particles is in the same direction as the energy transfer. An example of longitudinal waves is sound waves.

In a longitudinal wave, particles in the medium oscillate back and forth along the direction of the wave, creating areas of compression and rarefaction. In a transverse wave, particles in the medium oscillate up and down, creating crests and troughs.

Therefore, the correct statement is Particles in longitudinal waves travel in the direction of the wave, while particles in transverse waves travel perpendicular to the wave(D).

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which of the following statements about blood alcohol concentration (BAC) are true?
A. its illegal for a driver under 21 years of age of to drive with a BAC of 0.02% or above
B. it is illegal for a driver at any age to drive with a BAC of 0.08% or above
C. Both A and B are true
D. Neither A or B

Answers

D) Neither A or B are correct

determine the total voltage in the circuit below the ammeter is reading 4 A

Answers

Answer:

6 V.

Explanation:

We'll begin by calculating the equivalent resistance of the circuit. This can be obtained as follow:

Resistor 1 (R₁) = 3 Ω

Resistor 2 (R₂) = 3 Ω

Equivalent Resistance (R) =?

Since the two resistor are in parallel connection, the equivalent resistance can be obtained as:

R = (R₁ × R₂) / (R₁ + R₂)

R = (3 × 3) / (3 + 3)

R = 9/6

R = 1.5 Ω

Finally, we shall determine the total voltage in the circuit. This can be obtained as follow:

Current (I) = 4 A

Equivalent Resistance (R) = 1.5 Ω

Total voltage (V) =?

V = IR

V = 4 × 1.5

V = 6 V

Thus, the total voltage in the circuit is 6 V

The speed of a wave is 1500 m/s. What is the frequency of the wave if the wavelength is 2 m?
O 1502 Hz
O 750 Hz
O 375 Hz
O 300 Hz

Answers

Answer:

750 Hz

Explanation:

speed = freq * wl

 1500 =  f  * 2

    f = 750 Hz

What process changes a liquid to a solid?
A. Evaporation
B. Melting
C. Adding heat
D. Freezing

Thank you!!!<3

Answers

Answer:

D. Freezing?

Explanation:

Get water, put it in the freezer, turns into ice after a few hours.

5.) This car battery
measures at 12.6 V
with a voltmeter. If it
produces 0.53 A of current for
a vehicle's headlight when
connected, what is the
resistance of the headlight
bulb?

Answers

Answer:

R =V/ I =12.6 ÷ 0.53= 27.77 ohm

You leave a pastry in the refrigerator on a plate and ask your roommate to take it out before youget home so you can eat it at room temperature, the way you like it. Instead, your roommateplays video games for hours. When you return, you notice that the pastry is still cold, but thegame console has become hot. Annoyed, and knowing that the pastry will not be good if it ismicrowaved, you warm up the pastry by unplugging the console and putting it in a clean trashbag (which acts as a perfect calorimeter) with the pastry on the plate. After a while, you find thatthe equilibrium temperature is a nice, warmTeq.. You know that the game console has a mass ofm1. Approximate it as having a uniform initial temperature ofT1. The pastry has a mass ofm2and a specific heat ofc2, and is at a uniform initial temperature ofT2. The plate is at the sameinitial temperature and has a mass ofm3and a specific heat ofc3. What is the specific heat ofthe console

Answers

Answer:

   [tex]c_{e1} = \frac{(m_2 c_{e2} \ + m_3 c_{e3} ) \ (T_{Teq} - T_2) }{m_1 (T_1 - T_{eq}) }[/tex]

Explanation:

This is a calorimeter problem where the heat released by the console is equal to the heat absorbed by the cupcake and the plate.

           Q_c = Q_{abs}

where the heat is given by the expression

           Q = m c_e ΔT

            m₁ c_{e1) (T₁-T_{eq}) = m₂ c_{e2} (T_{eq} -T₂) + m₃ c_{e3} (T_{eq}- T₁)

note that the temperature variations have been placed so that they have been positive

They ask us for the specific heat of the console

           [tex]c_{e1} = \frac{(m_2 c_{e2} \ + m_3 c_{e3} ) \ (T_{Teq} - T_2) }{m_1 (T_1 - T_{eq}) }[/tex]

(TCO 6) A car travelling at 70 kilometers per hour hits a block wall and comes to a complete stop. If the time for the car to reach a complete stop is 450 ms and the wall does not move, how much force was exerted on the car? The mass of the car is 1500 kg.

Answers

Answer:

F = 64800 N

Explanation:

Given that,

Initial speed of a car, u = 70 km/h = 19.44 m/s

Finally it comes to a stop, v = 0

Time,t = 450 ms

The mass of the car is 1500 kg

We need to find the force exerted on the car. The force exerted on an object is given by :

F = ma

So,

[tex]F=\dfrac{m(v-u)}{t}\\\\F=\dfrac{1500\times (19.44-0)}{450\times 10^{-3}}\\\\F=64800\ N[/tex]

So, the required force is equal to 64800 N.

What is the resistance force when you walk up an inclined plane?
Please help quick!

Answers

Friction
Friction also affects the movement of an object on a slope. Friction is a force that offers resistance to movement when one object is in contact with another. Imagine now that you were on the downside of the object and applying force to keep the object in the same place (not moving)

The resistance force which is the type of force that oppose the motion when we walk on an inclined plane is mgcos (-).

What is Resistance force?

A Resistance force is defined as a force that acts to oppose the motion or motion of an object that is an opposing force. Resistance force opposes the moving body to move in the opposite direction. Resistive force is described as the force, or the vector sum of several forces where the direction is opposite to the motion of a body is also called friction during sliding and/or rolling.

Some examples of resistive force are friction, where an object is held back from sliding on a surface, while another form of resistive force is fluid resistance in which the object is trying to plow through a fluid material.

Thus, the resistance force which is the type of force that oppose the motion when we walk on an inclined plane is mgcos (-).

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a car is traveling with a velocity of 40 m/s and has a mass of 1120kg the car has kinetic energy

Answers

As shown in picture please give me Brainly list

2) __________ are chemical messengers produced by the endocrine system and released into the bloodstream.

BRAINLIEST!
NO FILE HOSTING LINKS!!!

Answers

Answer:

Hormones

Explanation:

The glands that make up the endocrine system produce chemical messengers called hormones that travel through the blood to other parts of the body. Important endocrine glands include the pituitary, thyroid, parathyroid, thymus, and adrenal glands

1. Fill in the blanks. (3 pts)
a.
is the amount of matter in an object.
b.
is the unit of measurement for force.
c.
p = m* v is

Answers

Answer:

a) mass

b) Newtons

c) momentum formula where p stands for momentum, m stands for mass, and v stands for velocity

Hope this helps!

Answer:

a mass

b acceleration

mass is the matter in an object

force is a pull or push of an object or body

A 5kg block rests on a 30° incline. The coefficient of static friction between the block and the incline is 0.20. How large a horizontal force must push on the block if the block is to be on the verge of sliding. a) up the incline, b) down the incline ? ​

Answers

Answer:

Hope It Help

Explanation:

That's all I know

An object has 4J of kinetic energy and 16J of potential energy. How much mechanical energy does it have?
A. 64J
B. 12J
C. 20J
D. 4J​

Answers

Answer: C. 20J

Explanation:  im pretty sure sorry if im wrong :(

describe the human condition before Science and technology was practice.​

Answers

Their condition was very very bad .doing everything by themselves

Which statement correctly describes the organization of cells, tissues, organs, and organ systems within a human body?

A.
Specialized organs work together in organ systems to form cells that come together in tissues.

B.
Specialized cells work together in organs to form tissues that come together in organ systems.

C.
Specialized cells work together in tissues to form organs that come together in organ systems.

D.
Specialized tissues work together in organ systems to form cells that come together in organs.

Answers

I think the answer is B

A disk of a radius 50 cm rotates at a constant rate of 100 rpm. What distance in meters will a point on the outside rim travel during 30 seconds of rotation? ​ ​

Answers

Answer:

the distance in meters traveled by a point outside the rim is 157.1 m

Explanation:

Given;

radius of the disk, r = 50 cm = 0.5 m

angular speed of the disk, ω = 100 rpm

time of motion, t = 30 s

The distance in meters traveled by a point outside the rim is calculated as follows;

[tex]\theta = \omega t\\\\\theta = (100 \frac{rev}{\min} \times \frac{2\pi \ rad}{1 \ rev} \times \frac{1\min}{60 s} ) \times (30 s)\\\\\theta = 100 \pi \ rad\\\\d = \theta r\\\\d = 100\pi \ \times \ 0.5m\\\\d = 50 \pi \ m = 157.1 \ m[/tex]

Therefore, the distance in meters traveled by a point outside the rim is 157.1 m

follow the chain of energy from a plant to a person riding a skateboard. explain what type of energy is being used at each step.
PLEASE HELP!!!!

Answers

Answer:

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A house is lifted from its foundations onto a truck for relocation. The house is pulled upward by a net force of 2850 N. This force causes the house to move from rest to an upward speed of 15 cm/s in 5.0 s. What is the mass of the house?​

Answers

Answer:

m = 95000 kg

Explanation:

Given that,

Net force acting on the house, F = 2850 N

Initial speed, u = 0

Final speed, v = 15 cm/s = 0.15 m/s

We need to find the mass of the house. Let the mass be m. We know that the net force is given by :

F = ma

Where

a is the acceleration of the house.

So,

[tex]F=m\dfrac{v-u}{t}\\\\m=\dfrac{Ft}{(v-u)}\\\\m=\dfrac{2850\times 5}{(0.15-0)}\\\\m=95000\ kg[/tex]

So, the mass of the house is equal to 95000 kg.

represent 11 by 9 on a number line​

Answers

Can I get some more information.

Before we make measurements, let's make sure we understand the circuit. 1. Select all of the following that correctly describe what a volt meter and ammeter measure. Select all that apply: A volt meter measures the potential difference (or voltage) across a circuit element. A volt meter measures the potential difference (or voltage) passing through a circuit element. A ammeter measures the electric current passing through a circuit element. A ammeter measures the electric current across a circuit element.

Answers

Answer:

the correct answers are a and c

Explanation:

In an electrical circuit there are two important quantities to measure, such as voltage and current.

Voltage is the potential difference between two points in a circuit

current is the number of electrons you pass through a given point per unit of time.

Now let's analyze each answer

a) true. The potential difference across an element

b) False. The potential difference is u field there is no physical entity that moves

c) True. The current is electrons in motion and these pass through the given element

d) False. There is a physical quantity that passes through the point

the correct answers are a and c

A car travelling at 25 m/s has momentum 20,000 Kgm/s, calculate the mass of the car.

Answers

[tex] \Large {\underline { \sf {Required \; Solution :}}}[/tex]

We have

Velocity of the car, v = 25 m/sMomentum of the car, P = 20,000 kg.m/s

We have been asked to calculate the mass of the car, m.

[tex]\qquad\implies\boxed{\red{\sf{ P = mv}}}\\[/tex]

P denotes momentumm denotes massv denotes velocity

[tex] \quad \twoheadrightarrow\sf { 20000 = 25m} \\ [/tex]

[tex] \quad \twoheadrightarrow\sf { \cancel{\dfrac{20000}{25}} = m} \\ [/tex]

[tex]\quad\twoheadrightarrow\boxed{\red{\sf{ m = 800 \; kg}}}\\[/tex]

Therefore, mass of the car is 800 kg.

One of the scientists suggests that he can build a
cooling system for the theoretical photovoltaic cells
Experiment 2, which will keep the cells 1°C cooler
dan normal but decrease their efficiency by 1%. The
teoretical photovoltaic cells capturing which frequency
ranges
, if any, would benefit from this cooling system?

Answers

Answer: SORRY

SORRY AM DOING IT FOR POINTS

Explanation:

A pendulum with a mass of 250 g is released from its maximum displacement of 5 degrees and swings with a simple harmonic motion. If the period is 4 seconds, calculate a) the length of the pendulum, b) the amplitude, c) frequency, d) maximum velocity, e) total energy, f) maximum height.

Answers

L=T2xg/4x3.14^2
16x9.8/4x3.14^2
Used your calculator plz

(a) The length of the pendulum is 3.96 m.

(b) The amplitude is 7.89 m.

(c) The frequency is 0.25 Hz.

(d) The maximum velocity is 12.38 m/s.

(e) The total energy is 9.67 J.

(f) The maximum height is 3.94 m.

Length of the pendulum

The length of the pendulum at the given parameters is determined using the following formula.

[tex]T = 2\pi \sqrt{\frac{l}{gcos(\theta)} } \\\\\frac{T}{2\pi } = \sqrt{\frac{l}{gcos(\theta)} }\\\\\frac{T^2}{4\pi ^2 } =\frac{l}{gcos(\theta)}\\\\l = \frac{gcos(\theta)T^2}{4\pi^2} \\\\l = \frac{(9.8)cos(5)\times (4)^2}{4\pi^2} \\\\l = 3.96 \ m[/tex]

Amplitude of the pendulum

The amplitude of the pendulum is calculated as follows;

mgLcosθ = ¹/₂FA

mgLcosθ = ¹/₂(mg)A

Lcosθ = ¹/₂A

A = 2Lcosθ

A = 2 x 3.96 x cos(5)

A = 7.89 m

Angular speed of the wave

[tex]\omega = \sqrt{\frac{g}{l} } \\\\\omega = \sqrt{\frac{9.8}{3.96} } \\\\\omega = 1.57 \ rad/s[/tex]

Frequency of the wave

ω = 2πf

f = ω/2π

f = (1.57) / (2π)

f = 0.25 Hz

Maximum velocity

The maximum velocity is calculated as follows;

v = Aω

v = 7.89 x 1.57

v = 12.38 m/s

Total energy

E = mgLcosθ

E = 0.25 x 9.8 x 3.96 x cos(5)

E = 9.67 J

Maximum height reached by the pendulum

h = Lcosθ

h = 3.96 x cos(5)

h = 3.94 m

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Determine the kinetic energy of a 2000 kg roller coaster car that is moving at the speed of 10 ms

Answers

Answer:

[tex]\boxed {\boxed {\sf 100,000 \ Joules}}[/tex]

Explanation:

Kinetic energy is energy due to motion. The formula is half the product of mass and velocity squared.

[tex]E_k= \frac{1}{2} mv^2[/tex]

The mass of the roller coaster car is 2000 kilograms and the car is moving 10 meters per second.

m= 2000 kg s= 10 m/s

Substitute these values into the formula.

[tex]E_k= \frac{1}{2} (2000 \ kg ) \times (10 \ m/s)^2[/tex]

Solve the exponent.

(10 m/s)²= 10 m/s * 10 m/s= 100 m²/s²

[tex]E_k= \frac{1}{2} (2000 \ kg ) \times (100 \ m^2/s^2)[/tex]

Multiply the first two numbers together.

[tex]E_k= 1000 \ kg \times (100 \ m^2/s^2)[/tex]

Multiply again.

[tex]E_k= 100,000 \ kg*m^2/s^2[/tex]

1 kilogram square meter per square second is equal to 1 Joule. Our answer of 100,000 kg*m²/s² is equal to 100,000 Joules.

[tex]E_k= 100,000 \ J[/tex]

The roller coaster car has 100,000 Joules of kinetic energy.

12. A glass plate 1 cm thick, of refractive index 1.50, is placed
between a point source of light of wave length 6000 Å and a
screen. The distance from the source to the screen is 4 cm.
How many waves are there between the source and the
screen?

Answers

Answer:

7

Explanation:

The light travels a total of 4 cm to the screen, of that, 3 cm is in air and 1 cm is in the glass plate.

The total number of wavelengths of light between the source and screen is just the number of wavelengths in air plus the number in the glass.

To determine the number of wavelengths in air, divide the thickness of air (3 cm) by the wavelength of the light (6000 Angstroms), converting units as needed.

The refractive index of the glass is 1.5. That means that the velocity of propagation of the light in the glass is 2/3 of what it is in air, and so the wavelength of the light in glass is 2/3 of what it is in air. So, divide the thickness of glass (1 cm) by the wavelength of the light in glass (6000 * 2/3).

Add the two values for the final answer

Calculate the speed of an object that travels 75m in 15s.

Answers

11.1847 is what I got, sorry if I’m wrong

Which type of force is needed to lift the weight?
A friction
B gravity
C pull
D push

Answers

b.gravity have a great day:)

A.) A gemstone of mass 1.8 kg compresses a scale's spring by 2.6 cm.
Determine the spring constant.

B.) How much would the spring in the previous question compress if a 5.2 kg mass was placed on the scale?

Answers

Explanation:

Given that,

Mass, m = 1.8 kg

Compression, x = 2.6 cm

We know that,

Force on spring = weight

So,

[tex]mg=kx[/tex]

Where

k is spring constant

[tex]k=\dfrac{mg}{x}\\\\k=\dfrac{1.8\times 9.8}{2.6\times 10^{-2}}\\\\k=678.46\ N/m[/tex]

(2) If m = 5.2 kg

[tex]x=\dfrac{mg}{k}\\\\x=\dfrac{1.8\times 9.8}{678.46}\\\\x=2.6 \ cm[/tex]

Hence, this is the required solution.

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HELP Math will give 25 brainly points 7a+5a^2+6a^0-3a^2-4a What is the function of cilia in the respiratory system? A. Move gases into the blood. B. Move food into the stomach. C. Move mucus into the throat. D. Move air into the lungs What is the value of z? Someone help me please thank you Pls help asap thx its about Operations with Exponents7.8.9.10. Can anyone help with these ? for brainiest:):):):):):):) As you know a cube with each side 4 m in length has a volume of 64m3. Each side of the cube is now doubled in length. What is the ration if the new volume to the old volume What do all animals, including vertebrates and invertebrates, have in common?Question 1 options:They have backbones, internal skeletons, and muscles.They are heterotrophs that must get their food from plants or other animals.They have lungs or gills for breathing.They are endothermic (warm-blooded).Question 2 (1 point) SavedAll animals share several common characteristics. Which is a characteristic shared by all animals?Question 2 options:endoskeletons and musclessensory organs and backbonesmulti-cellular bodiesexothermic blood systemsQuestion 3 (1 point) Sams teacher asked him to make observations about animals at the zoo. Sam went to the zoo and filled in these two charts that the teacher gave him.What is the main difference between the species in Group 1 and Group 2?Question 3 options:Group 1 has small organisms, Group 2 has large organisms.Group 1 are endothermic, Group 2 are exothermic. Group 1 are vertebrates, Group 2 are invertebrates.Group 1 has exoskeletons, Group 2 has soft bodies.Question 4 (1 point) Which of the following is a characteristic of all mammals?Question 4 options:lungshairtailboth 1 and 2Question 5 (1 point) What is the benefit of an arthropods exoskeleton.Question 5 options:It allows arthropods to breathe.It protects and supports the arthropods body.It allows the arthropod to get food.It allows the arthropod to see far distances.Question 6 (1 point) What do arthropods and segmented worms have in common?Question 6 options: They both have segmented bodies during some stage of their life.They both have hard outer shells that are unmovable. 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