If a runner is running at 100 meters per minute at the exact moment they cross the finish line of a race, it is the
instantaneous speed.

O True
O False

Answer:

true

Explanation:

400/20=20

Answer:

True

Explanation:

400/20=20mps

plz mark me as brainliest.

Answer:

Explanation:

Carbon dioxide controls the amount of water vapor in the atmosphere and thus the size of the greenhouse effect. Rising carbon dioxide concentrations are already causing the planet to heat up.

Answer:

B. They are smaller and made of rocky material

Explanation:

i think it's right??

Answer:

x = 2 meters.

Explanation:

Let the position (distance) of fulcrum to the load be x.

Given the following data;

Load = 40 kg

Effort (force) = 40 Newton

Effort arm = 4 - x

To find the position of the fulcrum, we would use the expression;

Effort * effort arm = load * load arm

40 * (4 - x) = 40 * x

160 - 40x = 40x

160 = 40x + 40x

160 = 80x

x = 160/80

x = 2 meters

Therefore, the position (distance) of fulcrum to the load is 2 meters.

Answer:

  K_{total} = 8.91 J

Explanation:

In this exercise you are asked to find the kinetic energy of the can of coca-cola

         K_total = K_ {Translation} + K_ {rotation}

the translational kinetic energy is

         K_ {translation} = ½ m v²

the kinetic energy of rotation is

         K_ {rotation} = ½ I w²

The moment of inertia of a cylinder is

           I = ½ m r²

we substitute

          K_ {total} = ½ m v² + ½ (½ m r²) w²

angular and linear velocity are related

          v = w r

we substitute

          K_ {total} = ½ m v² + ¼ m r² v² / r²

          K_ {total} = m v² (½ + ¼)

          K_ {total} = ¾ m v²

let's calculate

          K_ {total} = ¾ 0.33 6.00²

           K_{total} = 8.91 J

Answer:

1) C. The precise location of weather-related phenomena

2) C. It shows that the galaxies are moving farther away.

Explanation:

1) The global positioning system can be used in many ways, like in navigation, mapping and surveying the land. It is also used to observe the small changes taking place in the movement of objects on earth. They are usually used to study earthquakes.

2) When light from the galaxies is shifted towards the longer wavelengths, it is called red shift. When light shifts towards the shorter wavelengths, it is called blue shift. Big bang theory states how the primordial universe started expanding from a hot and dense singularity, in the process of evolution of the universe.

The  universe is expanding always. Galaxies that are a part of the universe keep expanding and move farther away from each other. The galaxies that are very far off appear to  move much faster than the nearby galaxies.

Answer:

A

Explanation:

To answer this, we can use process of elimination.

B: This question states that all matter has gravity. This is not correct. All matter is *effected* by gravity, but we do not have gravity inside of us.

C: If this were the case, we would all be floating off into space.

D: Same issue as question B.

The question is not complete, so i have attached an image of the complete question and the image of the sled on the ice.

Answer:

A) 3

B) 7

C) 5

D) 5

E) 5

Explanation:

A) Looking at the image attached, The force that will continue to move the sled toward the right and speeding up at a steady rate would have to be a force acting towards the right and has constant strength (magnitude).

Thus, option 3 is correct.

B) The force that will continue to move the sled toward the right and at Constant velocity will be when no force is applied because at constant velocity, acceleration is zero and thus force will also be zero.

Thus, option 7 is correct.

C) The force that will slow the sled when moving to the right at steady rate(constant acceleration) would be an opposite force which means a force towards the left with a constant strength (magnitude).

Thus, option 5 is correct.

D) The force exerted on the sled by a person when the sled is accelerating to the right would be the normal force exerted on the person by the ice).

Thus, option 5 is correct.

E) The reaction to the normal force exerted on the sled by the ice when the sled is accelerating to the left would be the normal force exerted by the sled on the ice

Thus, option 5 is correct

Model of the energy transformation of this system we can say about N and M in the model is M < N.

Energy is the ability or capability to do tasks, such as the ability to move an item (of a certain mass) by exerting force. Energy can exist in many different forms, including electrical, mechanical, chemical, thermal, or nuclear, and it can change its form.

The model shows the energy transformation in electrical appliance Fan the is lass of energy in form of heat so  M < N.

Model of the energy transformation of this system we can say about N and M in the model is M < N.

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Answer:

D and E

Explanation:

I had this quiz as well so-

Answer: Velocity of the ball just after the collision is -1.414 m/s.

Explanation:

As energy is conserved in a reaction so here, energy before collision will be equal to the energy after collision.

[tex]E_{before} = mgh = E_{after} = \frac{1}{2}mv_{o}^{2}[/tex]

where,

m = mass

g = gravitational energy = [tex]9.8 m/s^{2}[/tex]

h = height or length

[tex]v_{o}[/tex] = initial velocity

Also here, height is the length of wire. Let the height be denoted by 'L'. Therefore,

[tex]\frac{1}{2}mv_{o}^{2} = mgL\\v_{o}^{2} = 2gL\\v_{o} = \sqrt{2gL}\\= \sqrt{2 \times 9.8 m/s^{2} \times 1.11 m}\\= 4.66 m/s[/tex]

Formula used to calculate velocity after the collision is as follows.

[tex]v_{f ball} = v_{o} [\frac{m_{ball} - m_{block}}{m_{ball} + m_{block}}][/tex]

where,

[tex]v_{f ball}[/tex] = final velocity of ball after collision

[tex]m_{ball}[/tex] = masses of ball

[tex]m_{block}[/tex] = masses of block

Substitute the values into above formula as follows.

[tex]v_{f ball} = v_{o} [\frac{m_{ball} - m_{block}}{m_{ball} + m_{block}}]\\= 4.66 m/s [\frac{1.48 kg - 2.77 kg}{1.48 kg + 2.77 kg}]\\= 4.66 m/s \times (-0.303)\\= -1.414 m/s[/tex]

Thus, we can conclude that velocity of the ball just after the collision is -1.414 m/s.

Answer:

false

Explanation:

This statement is false since frictional force always reduces the speed of and object and also always acts opposite to the direction of a motion. The correct answer is False

FRICTION

Frictional force is a force that opposes motion of an object.

When an object is in motion, the speed of the object will be constant only when the forces acting on the object are balanced. That is, the frictional force balanced or equal to the force applied. A balanced force cannot change the speed and direction of an object in motion.

There will be change in speed and direction when forces acting on the object are not balanced.

Friction forces cannot change the speed and direction of an object. This statement is false since frictional force always reduces the speed of and object and also always acts opposite to the direction of a motion.

Therefore, the correct answer is False.

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Answer:

μ = tan θ

Explanation:

For this exercise let's use the translational equilibrium condition.

Let's set a datum with the x axis parallel to the plane and the y axis perpendicular to the plane.

Let's break down the weight of the block

         sin θ = Wₓ / W

         cos θ = W_y / W

         Wₓ = W sin θ

         W_y = W cos θ

The acrobat is vertically so his weight decomposition is

         sin θ = = wₐₓ / wₐ

         cos θ = wₐ_y / wₐ

         wₐₓ = wₐ  sin θ

         wₐ_y = wₐ cos θ

let's write the equilibrium equations

Y axis  

     N- W_y - wₐ_y = 0

     N = W cos θ + wₐ cos θ

X axis

        Wₓ + wₐ_x - fr = 0

         fr = W sin θ + wₐ sin θ

the friction force has the formula

         fr = μ N

         fr = μ (W cos θ + wₐ cos θ)

we substitute

         μ (Mg cos θ + mg cos θ) = Mgsin θ + mg sin θ

         μ = [tex]\frac{(M +m) \ sin \ \theta }{(M +m) \ cos \ \theta }[/tex]

         μ = tan θ

this is the minimum value of the coefficient of static friction for which the system is in equilibrium.

Answer:

Y = 31750 Pa = 31.75 KPa (For 24.5 N force)

Y = 312500 Pa = 312.5 KPa (For 250 N force)

Explanation:

Since the elongation is constant. Therefore, the strain will remain the same in both cases:

[tex]Strain = \frac{Elongation}{Original\ Length}\\\\Strain = \frac{0.032\ m}{0.2\ m}\\\\Strain = 0.16[/tex]

FOR A FORCE OF 25.4 N:

[tex]Stress = \frac{Force}{Area}\\\\Stress = \frac{25.4\ N}{0.005\ m^2}\\\\Sress = 5080\ Pa = 5.08\ KPa[/tex]

Now, for Young's Modulus:

[tex]Y = \frac{Stress}{Strain}\\\\Y = \frac{5080\ Pa}{0.16}[/tex]

Y = 31750 Pa = 31.75 KPa

FOR A FORCE OF 520 N:

[tex]Stress = \frac{Force}{Area}\\\\Stress = \frac{250\ N}{0.005\ m^2}\\\\Sress = 50000\ Pa = 50\ KPa[/tex]

Now, for Young's Modulus:

[tex]Y = \frac{Stress}{Strain}\\\\Y = \frac{50000\ Pa}{0.16}[/tex]

Y = 312500 Pa = 312.5 KPa

Explanation:

the impulse and momentum change on each object are equal in magnitude and opposite in directions. Thus the total momentum is reserved

They have no overall momentum at all. They are travelling in opposing directions yet having the same mass and velocity. Their momentum vectors add up to exactly zero when added together.

When two objects collide, opposite-direction forces of equal magnitude are exerted to each item. When there are such pressures, it usually happens that one item speeds up and gains momentum, while the other object slows down (lose momentum).

Think about a situation where two similar objects are going in opposite directions at the same speed. It's noteworthy to note that despite both items moving, the momentum of the system as a whole is zero because the oppositely oriented vectors cancel out.

Therefore, Every object experiences an equal but opposite change in impulse and momentum. Thus, the entire momentum is held back.

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Answer:

I want to say option C) Applied force and upthrust.

Explanation:

Sorry if my answer is wrong. You can look in your book or study up on the website.

Answer:

I think D. Infrared radiation.

Answer:

infrared radition

Explanation:

valid

Explanation:

According to the law of conservation of energy, energy can neither be created nor destroyed but can be changed from one form to another.

for example : electrical energy can be converted or changed into light energy, sound energy, heat energy etc. this proofs that the law can be trusted because, it has just been proven by the example above that it can be changed and into many forms

Answer:

    F = 5.6 10⁻¹¹ N

Explanation:

The magnetic force is given by

         F = q v x B

The bold  indicate vectors, the scalar form of this expression is

         F = q v B sin θ

in this case they indicate that the speed and the magnetic field are perpendicular, so the angle is 90º and the sin 90 = 1

         F = q v B

the magnitude of the force is

         F = 1.6 10⁻¹⁹  3.5 10⁷ 10

         F = 5.6 10⁻¹¹ N

Answer:

Explanation:

The kinetic energy of block will be converted into potential energy of spring .

If A be the amplitude of oscillations

1 /2 k A² = 1/2 m v²

17 A² = 1.1 x .46²

A² = .0137

A= 11.7 cm

B )

when x = .25 A = .25 x 11.7 = 2.9 cm

potential energy = 1/2 k x²

= .5 x 17 x ( .029 )² = .00715 J

kinetic energy = 1/2 m v²

1/2 m v²  +  .00715  = .5 1.1 x .46²

1/2 m v²  +  .00715  = .1164

1/2 m v² = .10925

.5 x 1.1 x v²=  .10925

v² = .1986

v = .4456 m /s

= 44.56 cm /s

Answer:

assesses C.) muscular endurance

Explanation:

Answer:

a) T = 1.69 s, b)  k = 0.825 N / m, c)  v = 1.46 feet/s, d) a = 5.41 ft / s²,

e)   v = - 1,319 ft / s,    a = - 2.70 ft / s², f) K = 4.8 10⁻³ J, U = 1.49 10⁻³ J

Explanation:

In a mass-spring system with simple harmonic motion, the angular velocity is

         w = [tex]\sqrt{\frac{k}{m} }[/tex]

a) find the period

angular velocity, frequency, and period are related

         w = 2π f = 2π / T

          f = 1 / T

          T = 1 / f

           T = 1 / 0.59

           T = 1.69 s

b) the spring constant

         w = 2π f

         w = 2π 0.59

         w = 3.70 rad / s

         w² = k / m

          k = w² m

          k = 3.70² 0.060

          k = 0.825 N / m

c) the maximum speed

simple harmonic movement is described by the expression

          x = A cos (wt + Ф)

speed is defined by

         v =[tex]\frac{dx}{dt}[/tex]

          v = -A w sin (wt + fi)

the speed is maximum when the cosine is ± 1

          v = A w

          v = 0.394 3.70

          v = 1.46 feet/s

d) maximum acceleration

            a = [tex]\frac{dv}{dt}[/tex]

            a = - A w² cos wt + fi

the acceleration is maximum when the cosine is ±1

            a = A w²

            a = 0.394 3.70²

            a = 5.41 ft / s²

e) velocity and acceleration for x = 6 cm

let's reduce the cm to feet

            x = 6 cm (1 foot / 30.48 cm) = 0.1969 foot

Before doing this part we must find the phase angle (Ф), the most common way to start the movement is to move the spring a small distance and release it, so its initial speed is zero for t = 0 s

let's use the expression for the velocity

           v = -A w sin (0 + Фi)

           0 = - A w sin Ф

so sin Ф = 0 which implies that Фi = 0

the equation of motion is

            x = A cos wt

            x = 0.394 cos 3.70t

we substitute

           0.1969 = 0.394 cos 370t

           3.70 t = cos⁻¹ (0.1969 / 0.394)

let's not forget that the angle is in radians

           3.70, t = 1.047

           t = 1.047 / 3.70

           t = 0.2826 s

we substitute this time in the equation for velocity and acceleration

           v = - Aw sin wt

           v = - 0.394 3.70 sin 3.70 0.2826

           v = - 1,319 ft / s

           a = - A w² cos wt

           a = - 0.394 3.70² cos 3.70 0.2826

           a = - 2.70 ft / s²

f) the kinetic and potential energy at this point

           K = ½ m v²

let's slow down to the SI system

           v = 1.319 ft / s (1 m / 3.28 ft) = 0.402 m / s

           K = ½ 0.060 0.402²

           K = 4.8 10⁻³ J

           U = ½ k x²

           U = ½ 0.825 0.06²

           U = 1.49 10⁻³ J

Answer:

A. The resonator behaves as a wave guide (a hollow pipe used as a transmission line). The characteristics of the pipe depend on the type of the wave to be transmitted.

Answer:

Cervical cancer

Explanation:

Chemotherapy is a common treatment or most cancers

Answer:

A

Explanation:

Answer:

Option"B" is correct.

Explanation:

when a body move with constant velocity then acceleration is zero.

If the acceleration of an object is 0, it means the velocity of an object is constant and not changing with respect to time,

So, the correct option will be :

=》B)Velocity is constant

Answer: A

Velocity is zero because the acceleration isn't affected, and velocity is the rate of change, so it can't be any other options.

Answer:

Explanation:

Answer:

trueeeeeeee..........mmmm...........

Answer:

b.) the diverge in incident beam of light

Explanation:

A lens refers to any refracting surface. The manner in which a lens is curved tells whether it is a concave(diverging) lens or a convex (converging) lens.

A convex lens is thicker at the center than at the edges. It makes light to converge at a point.

A concave lens is is thinner at the center than at the edges. It makes light to appear to diverge from a point, hence the answer above.