I need help for 2 ASAP I haven’t been able to figure it out :(

Answer:

The correct option is;

A) It is the only force acting on the block that is causes by microscopic interactions

Explanation:

The force of friction is the force due to the relative motion of two surfaces in the presence of a perpendicular force acting between the surfaces.

The force of friction comes into play from the additional effect of the adhesion that is present between surfaces, the roughness of the surfaces, the contamination or deformation of the surfaces which is generated by the microscopic interactions be between the two surfaces, rather than the applied force.

The characteristics of the friction force, you can find which statements are correct:

   D) It is the sum of all the microscopic contact forces between the bottom of the block and the surface.

The force is an image of the interactions between bodies, these interactions create binding energy that can be formed and broken, the friction force is the macroscopic sum of all these microscopic interactions between two different surfaces.

The magnitude of the friction force depends on the type of each surface, on rough surfaces the interaction area is high, therefore the friction force is high, on smooth surfaces the interaction area is small, therefore the force is small, a way to create superficiality is to place a layer of air between the two surfaces.

Based on these explanations, let's review the different statements:

A) False. The friction forces are caused by interaction, but between two bodies not within the same body, this is what maintains the shape and volume of the body.

B) False. The contact area depends on each surface and therefore each type of material

C) False. The gravitational force is this in the line of interaction between the two bodies, in this case the force is perpendicular to movement, not in the line of interaction.

D) True. It is the sum of the interactions in the contact between the two bodies, it agrees with the explanation above.

Using the characteristics of the friction force, we can find the statements that are correct is:

   D)  It is the sum of all the microscopic contact forces between the bottom of the block and the surface.

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Answer:

Explanation:

If a baseball is hit into the air with a velocity of 27 m/s, we want to determine the maximum height of the ball. Using the projecile formula;

Max height H = u²/2g

u is the initial velocity of the body = 27m/s

g is the acceleration due to gravity = 9.81m/s²

H = 27²/2(9.81)

H = 729/19.62

H = 37.16m

Hence the ball went 37.16m high

Answer:

True

Explanation:

A drug like cocaine causes more dopamine to be produced in the brain is True.

Dopamine is a type of neurotransmitter which can be a monoamine. This dopamine will be produced in brain and it acts as a chemical messenger which will be used to communicate messages between the nerve cells in the brain and to the brain and the other parts of the body.

When an individual who takes the drugs such as heroin, nicotine, cocaine and methamphetamine can increases or promotes the neurochemical reaction which will produce or increases the amount of dopamine that is a primary factor which can be the addiction that is secreted by neurons in the brain's reward center.

The functions of the reward center is memory, movement, motivation, mood, attention and more.

The diseases caused by dopamine are higher dopamine levels lead to pleasure in the mind of an addict and it makes people forget the pain or stress and gives immense pleasure.

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Answer:1.3  103 N

Explanation:hope this helps.

Increasing the charge on each particle by 2.0C would increase the electric force between the two particles. Therefore, option (B) is correct.

According to Coulomb’s law, the force between two charged point charges is the product of the magnitude of their charges and is inversely proportional to the square of the distance between the point charges. This force usually acts along the line which is joining the two charges.

The magnitude of the electric force can be expressed mathematically:

[tex]F = k\frac{q_1q_2}{r^2}[/tex]

where k is constant and has a value of 8.99 × 10⁹ N.m²/C².

We have given the two-point charges 8.1 C and 2.6 C. The distance between them is equal to 0.03 m. From the above-written formula, we can say that the charge on the particles is directly proportional to the electric force, and the distance between the charged particles is inversely proportional to the electric force.

Therefore, increasing the charge on each particle by 2.0 C would increase the electric force between the two particles.

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Answer:

Explanation:

a) The formulas for the components Vx and Vy of the velocity and components x and y of the displacement are given by x = V0 cos(θ)       Vy = V0 sin(θ) - g t

x = V0 cos(θ) t       y = V0 sin(θ) t - (1/2) g t2

In the problem V0 = 20 m/s, θ = 25° and g = 9.8 m/s2.

The height of the projectile is given by the component y, and it reaches its maximum value when the component Vy is equal to zero. That is when the projectile changes from moving upward to moving downward.(see figure above) and also the animation of the projectile.

Vy = V0 sin(θ) - g t = 0

solve for t

t = V0 sin(θ) / g = 20 sin(25°) / 9.8 = 0.86 seconds

Find the maximum height by substituting t by 0.86 seconds in the formula for y

maximum height y (0.86) = 20 sin(25°)(0.86) - (1/2) (9.8) (0.86) 2 = 3.64 meters

b) The time of flight is the interval of time between when projectile is launched: t1 and when the projectile touches the ground: t2. At t = t1 and t = t2, y = 0 (ground). Hence

V0 sin(θ) t - (1/2) g t2 = 0

Solve for t

t(V0 sin(θ) - (1/2) g t) = 0

two solutions

t = t1 = 0 and t = t2 = 2 V0 sin(θ) / g

Time of flight = t2 - t1 = 2 (20) sin(θ) / g = 1.72 seconds.

c) In part c) above we found the time of flight t2 = 2 V0 sin(θ) / g. The horizontal range is the horizontal distance given by x at t = t2.

range = x(t2) = V0 cos(θ) t2 = 2 V0 cos(θ) V0 sin(θ) / g = V02 sin(2θ) / g = 202 sin (2(25°)) / 9.8 = 31.26 meters

d) The object hits the ground at t = t2 = 2 V0 sin(θ) / g (found in part b above)

The components of the velocity at t are given by

Vx = V0 cos(θ)       Vy = V0 sin(θ) - g t

The components of the velocity at t = 2 V0 sin(θ) / g are given by

Vx = V0 cos(θ) = 20 cos(25°)       Vy = V0 sin(25°) - g (2 V0 sin(25°) / g) = - V0 sin(25°)

The magnitude V of the velocity is given by

V = √[ Vx2 + Vy2 ] = √[ (20 cos(25°))2 + (- V0 sin(25°))2 ] = V0 = 20 m/s

Explanation:

2.23 m/s^2 squared yung 2

Answer:

A

Explanation:

A lunar eclipse occurs when the Moon enters the Earth's shadow. A solar eclipse occurs when the Moon's shadow falls on the Earth. They do not happen every month because the Earth's orbit around the sun is not in the same plane as the Moon's orbit around the Earth.

Answer:

-1

Explanation:

Electrons have a negative charge and protons have a positive charge. (+11) + (-12) = -1

His mass is 50 kg . . . on the Moon, on the Earth, in the capsule rocketing between them, and on Halley's comet if he ever goes there.

Answer:

50kg

Explanation:

The mass of a man on the Earth and the moon is the same, so we only need to use the 490N weight on Earth.

The formula for mass is m=w/g. Plugging in the values, we can determine that m=490N/9.8m/s^2. (g is gravitational constant, which is approximately 9.8m/s^2 on Earth)

The reason that the unit in the answer is in kg is because one newton (N) is 1kg*m/s^2. The m/s^2 is cancelled out by the m/s^2 in the gravity constant, so it leaves kg.

m=50kg

When you ride your bike around a corner at 10 m/s, you are accelerating. Acceleration is caused by any forces. Sliding friction keeps you in the seat when a car goes around a corner. If you throw a ball into the air, Earth exerts a force on the ball.

Answer:

yes because acceleration is a vector quantity and as u turn around a corner you are changing direction.

Explanation:

Answer:

115.7g

Explanation:

Given parameters:

    Volume of copper  = 100cm³

    Mass of copper  = 890g

Unknown:

Mass of 13cm³ copper  = ?

Solution:

We know that the two materials are both made up of copper. Since we know the mass and volume of the first one, let us solve for the density. Using the density of the first one, we can determine the mass of the second one by the given volume.

Density is an intrinsic property of matter. It has the same value for every given substance.

It is expressed as mass per volume of  a substance;

    Density  = [tex]\frac{mass}{volume}[/tex]

Input the parameters and solve;

  Density  = [tex]\frac{890}{100}[/tex]  = 8.9g/cm³

Now to find the mass of the 13cm³ copper;

       Mass  = density x volume

       Mass  = 8.9 x 13  = 115.7g

Answer:

If an object has a net force acting on it, it will accelerate. The object will speed up, slow down or change direction. An unbalanced force (net force) acting on an object changes its speed and/or direction of motion. An unbalanced force is an unopposed force that causes a change in motion.

Explanation:

I hope this helps you out and if your feeling generous plz mark brainliest it helps me a lot thank you:)

Answer:

y = 15.61 [m]

Explanation:

To solve this problem we must use the following kinematics equation. We must bear in mind that the acceleration of gravity is negative since the direction of gravity is opposite to the direction of motion.

[tex]v_{f} ^{2} = v_{i} ^{2} -(2*g*y)[/tex]

where:

Vf = final velocity = 0

Vi = initial velocity = 17.5 [m/s]

g = gravity acceleration = 9.81 [m/s^2]

y = height [m]

The final speed is zero, since the ball reaches the maximum height its speed will be zero since it cannot be lifted up more.

0 = (17.5)^2 - (2*9.81*y)

306.25 = 2*9.81*y

y = 15.61 [m]

Answer:

A.) no reaction. Edge 2020.

Explanation:

There will be no reaction.

The activity series is also known as the reactivity series. It arranges elements in order of reactivity.

Given the activity series; F > Cl > Br > I, we need to predict whether the reaction; Br2 + NaF will proceed or not.

Looking at the reaction, Br is less than F in the activity series so Br can not displace F in NaF. Hence, there will be no reaction.

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Answer:

The power of the car, the gear ratio, weight of the car, aerodynamics of the car, grip of the tires on the road, calorific value of the fuel used, and friction would affect the speed of the car.

Answer:

I can't understand you're que... plzz write in a correct way..

Answer:

The nucleus has an overall positive charge as it contains the protons. Every atom has no overall charge (neutral). This is because they contain equal numbers of positive protons and negative electrons. These opposite charges cancel each other out making the atom neutral.

Explanation:

Answer:

3. The marble's trajectory was constantly being changed by running into the ring, forced it to move along the shape of the ring.

4. Once the ring was removed, the marble's momenum kept it going in a straight path as the ring was no longer forcing it to turn.

Explanation:

Answer: They will fall at the same time

Explanation:I had a google doc about this

When air resistance is considered, the effect of the air resistance will cause the rock to fall faster than the pebble which will be delayed due to its lesser weight. In the absence of air resistance, both rock and pebble will fall down at the same time.

Free fall is a motion of an object in which the force of gravity is the only force acting upon it. A body moving upwards would not be considered to be falling. But if the body falls under the effect of the force of gravity, it is said to be in free fall.

Free fall is a type of motion in which no air resistance is considered and the force acting upon an object is only gravity. All bodies under such conditions fall with an equal rate of acceleration, regardless of their masses.

As a body falls through the air, have suffered some degree of air resistance. Air resistance is the collisions of the surface of an object with molecules present in the air. The factors that have a direct effect on the amount of air resistance are the cross-sectional area and the speed of the object.

As the rock had greater weight than the pebble in the absence of air resistance it will fall faster than the pebble.

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Answer:

The sea level could have been much higher in the past.

Explanation:

The tectonic plates shifted and the mountain rose from there.

They are trapped throughout the rock whereas the seashells have been on the floor of a modest seafloor.

Thus the above response is appropriate.

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Answer:

i guess it will be mass or volume, but not sure

Explanation:

because the blocks volume will be same as the displaced water, then u will check the mass or volume of the water to see what the volume of a object will be.

Answer: D

Explanation: just completed this question on a p e x

Answer:

i think answer b

Explanation:

Answer: 90 km

Explanation: 60 * 1.5