Which is always true in a closed system?
Acceleration is not constant.
Mass is not conserved.
Momentum is conserved.
Velocity is constant.

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.

Read more the similar concept here;

brainly.com/question/24291110

#SPJ2

Answer:

revised

Explanation:

Answer:

Explanation:

Displacement is the diatnce moves in a specified direction. It is the shortest distance covered  by the dog. The displacement of the dog can be gotten by using the pythagoras theorem as shown;

According to the theorem, a²+b² = d² where d is the displacement

Substituting the given value into the fofrmula;

3²+4² = d²

9+16 = d²

d² = 25

square root both sides

√d² = √25

d = √25

d = 5 metres

Hence the displacement of the dog is 5metres

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

Answer:d

Explanation:tsssss

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

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:

A)   50 kg m/s

B)  2 kg m/s

C)  100 kg m/s

Explanation:

Recall that momentum is a physical quantity defined by the product of the object's mass times its velocity. Therefore, in our case the truck's momentum (p) is:

A)  p = m * v = 10 kg * 5 m/s = 50 kg m/s

B) p = m * v = 10 kg * 0.20 m/s = 2 kg m/s (notice that the velocity in cm/s was converted into m/s before multiplying)

C) the conversion from km/h to m/s is a little more involved, so we taclke it first:

since 1 km = 1000 m  and 1 hour = 3600 seconds, we convert 36 km/h by replacing each unit by its m and s expression as shown below:

[tex]36 \frac{km}{h} =36\,\frac{1000\,m}{3600\,\,s}=10\,\frac{m}{s}[/tex]

Then, the momentum is:  p = m * v = 10 kg * 10 m/s = 100 kg m/s

Answer:

Muller-Lyer optical illusion

Answer: Molecules

Explanation:

Answer:

B. molecules

Explanation:

got 100% on the edge quiz

The above are questions related to the formula of force F = m * a i.e. mass * accleration. It is defined by the Newton's second law of motion.

In the attachment, I can see that Question 1) and Question 2) are already done, So lemme start from Question 3[tex])[/tex]

3) Provided:-

To FinD:-

By using formula,

⇛ F = ma

⇛ 7000 N = 0.5 kg × a

⇛ a = 7000 / 0.5 m/s²

⇛ a = 14000 m/s²

So, the ball acclerates at the rate of 14000 m/s².

4) Provided:-

To FinD:-

By using formula,

⇛ F = ma

⇛ F = 31200 kg × 10 m/s²

⇛ F = 312000 kg/m/s²

⇛ F = 312000 N

So, force on the truck = 312000 N

5) a) Force applied = 100 N

Mass applied = 5 kg

Then, Acceleration = 100 ÷ 5 = 20 m/s²

b) Force applied = 100 N

Mass applied = 10 kg

Then, Acceleration = 100 ÷ 10 = 10 m/s²

c) Force applied = 100 N

Mass applied = 20 kg

Then, Acceleration = 100 ÷ 20 = 5 m/s²

d) Force applied = 100 N

Mass applied = 50 kg

Then, Acceleration = 100 ÷ 5 = 2 m/s²

And we are done !!

#CarryOnLearning

━━━━━━━━━━━━━━━━━━━━

Answer: The answer are above :(

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:

area = force by pressure

or, a = 120N by 60000 Pa

or, a= 0.002 m²

Answer:

Acceleration, [tex]a=-2.8\ m/s^2[/tex]

Explanation:

It is given that,

The initial speed of a speed skater, u = 8 m/s

The final speed of a speed skater, v = 6 m/s

Width of patch of rough ice, s = 5 m

We need to find the acceleration on the rough ice. Acceleration can be calculated using third equation of motion as :

[tex]v^2-u^2=2as\\\\a=\dfrac{v^2-u^2}{2s}\\\\a=\dfrac{(6)^2-(8)^2}{2\times 5}\\\\a=-2.8\ m/s^2[/tex]

So, the acceleration on the rough ice is [tex]2.8\ m/s^2[/tex]. Negative sign shows that its speed is decreased.

Answer:

Explanation:

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.​

To learn more about diffusion refer to;

https://brainly.com/question/13513898

#SPJ2

Answer:

Less

Explanation:

because static friction is more than rolling friction

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:

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

Answer:

75

Explanation:

w

X

y

z.86.2,86.7,70.8

Answer:

45 m

Explanation:

Initial velocity of the coin = 0 m/s  (since he dropped it from his hands)

time spent in falling - 3 sec

distance s = ?

using

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

where

s is the distance the stone fell

u is the initial velocity

t is the time spent falling

g is acceleration due to gravity = 10 m/s^2 (positive downwards)

substituting values, we have

s = (0 x 3) +  [tex]\frac{1}{2}[/tex](10 x [tex]3^{2}[/tex])

s = 45 m

Answer:

Thermal and Radiant

Explanation:

Thermal = Heat

Radiant = Light

Answer: B

Explanation:

Answer:

10 hours to get to Paris

Answer:

you have to organize the data. a= acceleration vi=inicial velocity vf=final velocity  t=time.

a=80m/s

vi=0

vf=?

t=40 s

the formula you have to use is:

vf=vi+a*t  (final velocity= inicial velocity plus acceleration times time)

Explanation:

I was the best one at my class, hope it helped

Answer: 320 m/s

Explanation:  V initial = 0, V final= ?   Acceleration = 8m/s/s  t=40s

Answer:

Velocity=0.2m/s

Explanation:

Velocity=displacement / time

Velocity=7.6m/38s

Velocity=0.2m/s

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:

Explanation:

velocity is the change in displacement of a body with respect to time. Given the displacement d (m) of a block sliding along a straight line is given by the equation d = -0.65 t + 0.21 t², where t is the time in seconds, instantaneous velocity is expressed by differentiating the displacement with respect to time

Velocity = dd/dt

Velocity = -0.65 + 2(0.21)t²⁻¹

Velocity = -0.65 + 0.42t

The instantaneous velocity of the block when t = 2.0 s can be gotten by substituting t = 2.0s into the expression above:

Velocity = -0.65 + 0.42(2)

Velocity = -0.65 + 0.84

Velocity = 0.19

Hence the instantaneous velocity of the block when t = 2.0 s is 0.19m/s

Answer:

3.70149

Explanation: