Melissa and Rory live near a bike trail, 21 km apart. They plan to meet at a park mid-way between their homes. They start from their homes at the same moment, and ride toward each other. Both ride at 7 km/hour. Melissa’s dog Jessie knows this routine. He starts with Melissa, and runs at 18 km/hour toward Rory. When he reaches Rory, he turns around and runs toward Melissa. He reaches Melissa, turns around and runs toward Rory again, and so on, until Melissa and Rory meet. How many kilometers did Jessie run?

Answer:

1.) h = 164.8 m

2.) U = 49.1 m/s

3.) t = 1.43 seconds

Explanation:

1.) A soccer ball is dropped from the top of a building. It takes 5.8 seconds to fall to the ground. The height of the building is...? 

Since the soccer ball is dropped from the building, the initial velocity U will be equal to zero

Using second equation of motion

h = Ut + 1/2gt^2

Substitutes the time into the formula

h = 1/2 × 9.8 × 5.8^2

h = 164.8 m

2. The Falcon 9 launches to a height of 123 meters. What is its vertical initial velocity?

At maximum height final velocity = 0

Using the third law of motion

V^2 = U^2 - 2gH

0 = U^2 - 2 × 9.8 × 123

U^2 = 2410.8

U = 49.1 m/s

3. An apple falls from rest off a 10.m m tree. How long will it take before it hits the ground?

Since the apple fall from rest, the initial velocity U will be equal to zero

Using the second equation of motion,

h = Ut + 1/2gt^2

substitute all the parameters into the formula

10 = 1/2 × 9.8 × t^2

10 = 4.9t^2

t^2 = 10/4.9

t^2 = 2.04

t = 1.43 seconds

We don't know, and we don't have enough information to calculate it.

The weight of the 60kg load is (m g) = 588 Newtons.

IF Hari wanted to lift the load 12m straight up, he would have to do

(Force x distance) = (588 N) x (12 m) =  7,056 Joules of work.

But to drag it, he has to provide enough force to balance out the force of friction, and we don't know how much that is. It depends on the weight of the load, the shape of the load, the smoothness of the part of the load that sits on the ground, and the smoothness of the ground.  But the only thing we know is the weight of the load.

Answer = (100 billion stars/galaxy) x (100 billion galaxies/universe)

Answer = (100 billion x 100 billion) stars

Answer = 10,000 billion billion stars

Answer = 10,000,000,000,000,000,000,000 stars

Answer = 10²² stars/observable universe

The number of stars in the observable universe is; 10²² stars/observable universe.

Since there are about 100 billion stars in our galaxy; we can rewrite that to be;

100 billion stars/galaxy

However, there are about 100 billion galaxies in the observable universe.

Since our galaxy is one of the 10¹¹ observable galaxies in the universe; the number of stars in the observable universe is;

(100 billion stars/galaxy) x (100 billion galaxies/universe)

= (100 billion x 100 billion) stars

= 10,000 billion billion stars

= 10,000,000,000,000,000,000,000 stars

= 10²² stars/observable universe

Therefore, the number of stars in the observable universe is; 10²² stars/observable universe.

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Answer:

Yes

Explanation:

Answer: false

a theory is just an idea, so it can be changed, while a scientific fact is true and wont be changed

The statement is TRUE.

"Displacement" means the distance and direction from the start-point to the end-point, NO MATTER how you got there.

If you go out cycling and go back home when you're done, your displacement is zero.  it doesn't matter how far you cycled, or what streets or woods you cycled through, or whether your route was a circle, a square, an ellipse, a triangle, or a jumble, or whether you cycled around and around the same path 27 times.  You ended right where you started.  The distance from your start-point to your end-point is zero, so your displacement is zero.

Answer:

10 hours to get to Paris

Available Options Are:

A.SALT

B.STONE

C.GHEE

D.SPONGE

Answer:

Option A. Salt

Explanation:

The reason is that the all of the grains of salt are not in a unified shape. Some of these have large shape, some has small shape and the best think is that their shape doesn't resemble with each other. This is also because that the salt includes many other ingrediants that form part of the grain. Hence Salt is the correct Option.

Stone has a unified pattern shape hence it doesn't have irregular pattern.

Ghee also has unified shape pattern due to one compound existence and also because of liquid particles that has highest rate of reqular patterns.

Sponge is a compound product and has one compound existence thus the pattern of the particles will be regular.

Answer:

Georges Lemaître  - theorized that the universe had a beginning

Albert Einstein  - huit a model of the inverse haced on relativity

Galileo Galilei  - was the first to use a telescope to observe the planets

Edwin Hubble  - showed that the universe was expanding

Henrietta Swan Leavitt  - demonstrated a method to calculate the distance of celestial bodies

is my choices report if wrong

Galileo Galilei was the first to use a telescope to observe the planets

Albert Einstein built a model of the universe based on relativity

Henrietta Swan Leavitt demonstrated a method to calculate the distance of celestial bodies

Edwin Hubble showed that the universe was expanding

Georges Lemaître theorized that the universe had a beginning

Science is the methodical, empirically-based pursuit and application of knowledge and understanding of the natural and social worlds.

A method of learning about the world is science. Science allows people to participate in the creation of new knowledge as well as use that knowledge to further their goals. It is both a process, a product, and an institution.

Thus, The first person to observe the planets through a telescope was Galileo Galilei.

Based on relativity, Albert Einstein created a model of the universe.

A technique to determine the separation between celestial bodies was demonstrated by Henrietta Swan Leavitt.

Edwin Hubble demonstrated the expansion of the universe

According to Georges Lemaître, the universe had a beginning.

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Answer:

time stirred and amount of water

all of the answers are true

Answer:

All are True

Explanation:

Energy is both coming and leaving and so on.

Answer:

2.16 meters

Explanation:

We can find distance using the following formula.

[tex]d=s*t[/tex]

where [tex]s[/tex] is the speed and [tex]t[/tex] is the time.

The speed of the watermelon seed is 1.8 meters per second. The time is 1.2 seconds.

[tex]s= 1.8 m/s\\t=1.2 s[/tex]

Substitute the values into the formula.

[tex]d= 1.8 m/s * 1.2 s[/tex]

Multiply. When you multiply the 2 "s" that represent seconds will cancel out.

[tex]d= 1.8 m * 1.2[/tex]

[tex]d=2.16 m[/tex]

The watermelon seed with travel 2.16 meters in 1.2 seconds.

Answer:

This whole concept depends on the depends on the direction of propagation of the surface wave or displacement of wave such that if its in direction of wave velocity its said to features of longitudinal wave and if its in direction at 90° to wave velocity its said to have transverse features

Explanation:

because when diffusion occurs it is as a result of the particles moving around freely in open space

The fact that matter is composed of particles and that these particles are incredibly tiny and have space between them supports the theory that matter is composed of particles.

The mixing of materials is caused by the free movement of their particles is known as diffusion.

Even with a strong microscope, the substance is composed of microscopic particles that cannot be seen. The matter is anything that is both mass- and space-having. Small particles make up matter.

Because the particle's unrestricted movement in an open environment causes diffusion to happen.

Hence, diffusion supports the idea that matter is made up of particles.​

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Answer:

The toy must calculate the person's speed/velocity

Explanation:

Since the school toy given to Henry can be used to tell how fast someone is moving, the toy must be able to calculate the person's speed/velocity using the average distance covered by the person divided by time taken to cover the distance; average distance ÷ time taken.

The toy must be able to determine the parameters (average distance and time taken) in order to be able to calculate the person's speed/velocity

Answer:

240cm

Explanation:

Speed = 6cm/s

Time = 40 seconds

Speed= distance/time

6cm/s = distance/40seconds

Distance = 6×40

Distance = 240cm

Hence, in 40 seconds, the ball must have rolled the distance of 240cm

Answer:

The mass of an object is a measure of the object's inertial property, or the amount of matter it contains. The weight of an object is a measure of the force exerted on the object by gravity, or the force needed to support it. The pull of gravity on the earth gives an object a downward acceleration of about 9.8 m/s2.

Answer:

revised

Explanation:

Answer:Science is a method of learning things about the world and environment we live in today . It gives us a better understanding of the natural world and how it works

Explanation:

Answer:

t = 12.25 s

Explanation:

First we calculate the time taken by the car during accelerating motion, we use 1st equation of motion:

Vf = Vi + at₁

where,

Vf = Final Velocity = 21 m/s

Vi = Initial Velocity = 0 m/s

a = acceleration = 3 m/s²

t₁ = time taken during acceleration = ?

Therefore,

21 m/s = 0 m/s + (3 m/s²)t₁

t₁ = (21 m/s)/(3 m/s²)

t₁ = 7 s

Now, we use the same equation to find out the time taken during deceleration motion, with following data:

Vf = Final Velocity = 0 m/s

Vi = Initial Velocity = 21 m/s

a = deceleration = -4 m/s²

t₂ = time taken during deceleration = ?

Therefore,

0 m/s = 21 m/s + (-4 m/s²)t₂

t₂ = (-21 m/s)/(-4 m/s²)

t₂ = 5.25 s

Therefore, the total time taken by the car to travel from first stop sign to second stop sign is:

t = t₁ + t₂

t = 7 s + 5.25 s

t = 12.25 s

Answer:

12.25s

Explanation:

Answer:Vitamin K is an important factor in bone health and wound healing. Vitamin K is a fat-soluble vitamin that makes proteins for healthy bones and normal blood clotting. According to the Harvard School of Public Health, vitamin K helps produce four of the 13 proteins needed for blood clotting.

Explanation:

Hello! The answer to this would be 94m/s3 I believe. I’m not for sure with the units but in order to find the answer, you would need to use the equation Vf=VI+(a x t) you would plug in the numbers, so in you case you would plug in, Vf= 4m/s +(3m/s2 x 30s) and you would get solve. I’m so sorry that I’m not certain with the units but I hope this helps you understand! Good luck :)

Her final velocity is 94 m/s West, and her legs are all blurry because she is running at a little bit over 210 mph. Bet she can't keep that up for too long.

Answer:

Thermal and Radiant

Explanation:

Thermal = Heat

Radiant = Light

Answer: B

Explanation:

The phenomenon is called as condensation in which the water droplets combine together to form clouds. So, the correct option is D.

Condensation is defined as the change of state of matter from the gas phase to the liquid phase, and is the reverse of evaporation which often refers to the water cycle.

Condensation is described as the process where water vapor becomes liquid which is the opposite of evaporation, where liquid water becomes vapor. Condensation happens in one of two ways which are as follows: either the air cools to its dew point or it becomes so saturated with water vapor that it cannot hold any more water.

Thus, the phenomenon is called as condensation in which the water droplets combine together to form clouds. So, the correct option is D.

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Your question is incomplete, most probably the complete question is :

Which process must occur for clouds to form?

(1) conduction (2)erosion (3) precipitation (4) condensation

Focal length of convex lens is taken positive.

[tex]:\implies\sf\:\dfrac{1}{v}-\dfrac{1}{u}=\dfrac{1}{f}[/tex]

[tex]:\implies\sf\:\dfrac{1}{v}-\dfrac{1}{(-30)}=\dfrac{1}{20}[/tex]

[tex]:\implies\sf\:\dfrac{1}{v}=\dfrac{1}{20}-\dfrac{1}{30}[/tex]

[tex]:\implies\sf\:\dfrac{1}{v}=\dfrac{3-2}{60}[/tex]

[tex]:\implies\:\boxed{\bf{\gray{v=60\:cm}}}[/tex]

Answer:

[tex] \boxed{\sf Maximum \ tension \ (T_{max}) = 224 \ N} [/tex]

Given:

Mass (m) = 8 kg

Constant speed (v) = 6 m/s

Radius of vertical circle (r) = 2 m

Accelration due gravity (g) = 10 m/s²

To Find:

Maximum tension in the string ([tex] \sf T_{max} [/tex])

Explanation:

As the object is moving in a vertical circular path. So, the maximum tension on the string is when the body will be on its lowest position because at that point centrifugal force and force due to gravity both will act on the body in same direction.

So,

Maximum tension ([tex] \sf T_{max} [/tex]) is the string will be equal to centrifugal force ([tex] \sf F_c [/tex]) + Force due to gravity.

[tex] \boxed{ \bold{ T_{max} = F_c + mg= \frac{m {v}^{2} }{r} + mg }}[/tex]

Substituting value of m, v, r & g in the equation:

[tex] \sf \implies T_{max} = \frac{8 \times {6}^{2} }{2} + 8 \times 10 \\ \\ \sf \implies T_{max} = \frac{8 \times 36}{2} + 80 \\ \\ \sf \implies T_{max} = \frac{8 \times 36}{2} + 80 \\ \\ \sf \implies T_{max} = \frac{288}{2} + 80 \\ \\ \sf \implies T_{max} = 144 + 80 \\ \\ \sf \implies T_{max} = 224 \: N [/tex]

[tex] \therefore[/tex]

Maximum tension in the string (T) = 224 N

Answer:

Less

Explanation:

because static friction is more than rolling friction

Answer:

Velocity=0.2m/s

Explanation:

Velocity=displacement / time

Velocity=7.6m/38s

Velocity=0.2m/s

Answer:

3.70149

Explanation:

Answer:

A.) 1430 metres

B.) 80 seconds

Explanation:

Given that the train accelerates from rest at 1.1m/s^2 for 20s. The initial velocity U will be:

U = acceleration × time

U = 1.1 × 20 = 22 m/s

It then proceeds at constant speed for 1100 m

Then, time t will be

Time = distance/ velocity

Time = 1100/22

Time = 50 s

before slowing down at 2.2m/s^2 until it stops at the station.

Deceleration = velocity/time

2.2 = 22/t

t = 22/2.2

t = 10s

Using area under the graph, the distance between the two stations will be :

(1/2 × 22 × 20) + 1100 + (1/2 × 22 × 10)

220 + 1100 + 110

1430 m

The time taken between the two stations will be

20 + 50 + 10 = 80 seconds

Answer: Molecules

Explanation:

Answer:

B. molecules

Explanation:

got 100% on the edge quiz