1. A book is at rest on a tabletop. Diagram the forces acting on the book. ​

The box has 3 forces acting on it:

• its own weight (magnitude w, pointing downward)

• the normal force of the incline on the box (mag. n, pointing upward perpendicular to the incline)

• friction (mag. f, opposing the box's slide down the incline and parallel to the incline)

Decompose each force into components acting parallel or perpendicular to the incline. (Consult the attached free body diagram.) The normal and friction forces are ready to be used, so that just leaves the weight. If we take the direction in which the box is sliding to be the positive parallel direction, then by Newton's second law, we have

• net parallel force:

∑ F = -f + w sin(35°) = m a

• net perpendicular force:

∑ F = n - w cos(35°) = 0

Solve the net perpendicular force equation for the normal force:

n = w cos(35°)

n = (15 kg) (9.8 m/s²) cos(35°)

n ≈ 120 N

Solve for the mag. of friction:

f = µ n

f = 0.25 (120 N)

f ≈ 30 N

Solve the net parallel force equation for the acceleration:

-30 N + (15 kg) (9.8 m/s²) sin(35°) = (15 kg) a

a ≈ (54.3157 N) / (15 kg)

a ≈ 3.6 m/s²

Now solve for the block's speed v given that it starts at rest, with v₀ = 0, and slides down the incline a distance of ∆x = 3 m:

v² - v₀² = 2 a ∆x

v² = 2 (3.6 m/s²) (3 m)

v = √(21.7263 m²/s²)

v ≈ 4.7 m/s

Answer:

umm I also need help sorry

Explanation:

help..

Answer:

1.07 X 10^15 kg

Explanation:

Answer:

When an atom has an equal number of electrons and protons, it has an equal number of negative electric charges (the electrons) and positive electric charges (the protons). The total electric charge of the atom is therefore zero and the atom is said to be neutral.

Explanation:

An atom has an equal quantity of positive and negative electric charges (the protons and electrons) when its electron and proton counts are equal (the protons). Since the atom has a total electric charge of zero, it is referred regarded as being neutral.

The atom is the smallest unit of matter that may be divided without resulting in electrically charged particles. Additionally, it is the tiniest substance with features like chemical elements. The atom is therefore the basic building block of chemistry.

Examine different electron arrangements in the electron shells that surround an atom's nucleus.

Examine different electron arrangements in the electron shells that surround an atom's nucleus. The rest is made up of a cloud of negatively charged electrons surrounding a positively charged nucleus made up of protons and neutrons. Compared to electrons, which are the lightest charged particles in nature, the nucleus is small and dense.

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Answer: B

Explanation: Yes it is b, because the lightbulb won’t matter just the circuit and flow of the cable.

Answer:

hmmmmmmmmmmmmmmm

yes.

Answer:

i dont know dude but ask someone who is in your grade lol

Explanation:

Answer:

8.89 m/s

Explanation:

rate = distance/time

40m/4.5 sec = 8.8888889 m/s

Answer:

2

Explanation:

A huge enormous gigantic number ... two in every molecule of the stuff !

Answer:

Explanation:

The potential energy of a body can be found by using the formula

PE = mgh

where

m is the mass

h is the height

g is the acceleration due to gravity which is 9.8 m/s²

From the question we have

PE = 4812 × 9.8 × 203

We have the final answer as

Hope this helps you

Answer:

Space Weather Data

They are used to produce forecasts, such as the monthly sunspot number forecast. Most notably, sunspot numbers represent one of the longest continuous climate records available. The data give scientists the means to make many forecasts and issue space weather advisories and alerts.

Explanation:

Answer:

about 1.48 grams

Explanation: None

Answer:

Actually, the sun goes a bit down, like it's not all the way up as to summer. How I know is that you actually can go online maybe search for some videos and see proof, I don't really know how to explain it.

Explanation:

Reason #1: If you check, go out for 12 hours and see, I think the sun is a little down.

Reason #2:

The earth’s axis is tilted.

From a Brainly user of this question for more info:

The Earth is NOT farther away from the sun in USA Winter, and NOT closer to the sun in USA Summer. In 2021, we will be NEAREST to the sun on January 2, and FARTHEST from the sun on July 5 !

NEAREST to the sun next Saturday.

FARTHEST from the sun next July 5.

Answer: The coefficient of friction is 0.35

Explanation:

We can write the friction force as:

F = N*μ

Where N is the normal force between the refrigerator and the ground, as the full weight of the refrigerator is acting on the ground, the normal force will be exactly equal to the weight of the refrigerator, then:

N = 650N

And μ is the coefficient of friction.

And for this case, the force is 230N, then we have:

F = N*μ

230N = 650N*μ

(230N/650N) = μ = 0.35

Notice that the distance did not matter for this calculation.

Answer:

non-accelerated movement

velocity versus time  a horizontal straight line.

distance versus time  gives a horizontal straight line.

accelerated motion

graph of velocity versus time s an inclined line and the slope

graph of distance versus time is a parabola of the form

Explanation:

In kinematics there are two types of steely and non-accelerated movements

In a  the velocity of the body is constant therefore a speed hook against time gives a horizontal straight line.

A graph of distance versus time is a straight line whose slope is the velocity of the body

          x = v t

In an accelerated motion the velocity changes linearly with time, so a graph of velocity versus time is an inclined line and the slope is the value of the acceleration of the body

         v = v₀ + a t

A graph of distance versus time is a parabola of the form

         x =v₀ t + ½ a t²

Answer: 55n

Explanation:

Answer:

vibrating objects.

I think

Waves are often caused by vibrating objects. Based on the type of vibrational motion, there are different types of waves. Hence, option a is correct.

Waves are disturbances in air or the passage of energy through vacuum or through a medium. Waves are caused by vibration of objects. Three are two types of waves broadly, mechanical waves and electromagnetic waves.

Electromagnetic waves are those associated with combined electric and magnetic field. They can pass through both vacuum and mediums. Mechanical waves need a medium to pass and does not transfer through vacuum.

Based on the vibrational motion, there are two types of waves longitudinal waves and transverse waves. In transverse waves, the vibrational motion of particles is perpendicular to the wave propagation.

In the case of transverse waves, the particle vibration is along the wave propagation. Hence, option A is correct.

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Answer: Oceanic crust, the outermost layer of Earth's lithosphere that is found under ... Sort out the facts and see how deep your knowledge goes in this quiz of the world's oceans. ... They commonly are thin (only about 10 cm [4 inches] thick) and cover a ... km (85 square miles) of seafloor to an average depth of 70 metres (230 feet).

Explanation:

Answer:

The mitochondria is a cell organelle that provides energy for the cells.

Explanation:

A cell can be defined as the fundamental or basic functional, structural and smallest unit of life for all living organisms. Some living organisms are unicellular while others are multicellular in nature.

A unicellular organism refers to a living organism that possess a single-cell while a multicellular organism has many (multiple) cells.

All living organisms such as plants and animals require energy to function properly (life activities). Thus, the organelle where energy from nutrients is released is generally referred to as mitochondria.

Animals retrieve energy using mitochondria to do cellular respiration because they typically act like a digestive system by taking in nutrients, breaking them down and obtaining energy rich molecules for cell-life activities.

Basically, mitochondria is one of the cell organelles found in all living organisms and it is known as the powerhouse. Therefore, mitochondria provides all the energy required in the cell by transforming energy forms through series of chemical reactions; breaking down of glucose into Adenosine Triphosphate (ATP) used for providing energy for cellular activities in the body of living organisms.

Answer:

Carbon Dioxide.

Explanation:

Answer:

The time it takes the body to cover the remaining H/4 is T

Explanation:

The maximum height attained by the body = H

The time it takes the body to reach 3/4×H = T

From the kinematic equation, h = u·t - 1/2·g·t², we have;

u = 0 m/s at for the object returning back down at maximum height, therefore at the maximum height, we have;

H = u × 0 + 1/2·g·t²

H = 1/2·g·t²

t = √(2·H/g)

When h = 3/4×(H) from below, we have;

h = H/4 from above, which gives;

[tex]t_{H/4}[/tex] = √(2·H/4/g) = √(H/(2·g)) = 1/2 × √(2·H/g)

∴ The time it takes the body to cover H/4 height, while falling from above [tex]t_{H/4}[/tex] = 1/2 × √(2·H/g)  

The time, [tex]t_{3 \times H/4}[/tex], it takes to cover the remaining 3/4×(H) while falling from above is [tex]t_{3 \times H/4}[/tex] = T = t - 1/2 × √(2·H/g) = √(2·H/g) - 1/2 × √(2·H/g) = 1/2 × √(2·H/g)

∴ T = 1/2 × √(2·H/g)

Therefore, the time it takes the body to reach a height of 3/4H = The time it takes the body to cover the remaining H/4 = T.

(last choice)

The speed increases from X to W because a component of the gravitational force acts in the direction of the velocity.

D)The speed increases from X to W because a component of the gravitational force acts in the direction of the velocity.

The gravitational force is inversely proportional to the square of the separation distance between the 2 interacting gadgets, extra separation distance will result in weaker gravitational forces. so as items are separated from every other, the pressure of gravitational attraction between them also decreases.

The force of gravity relies immediately upon the masses of the 2 gadgets, and inversely on the square of the gap between them. this means that the pressure of gravity will increase with mass, but decreases with growing distance among items.

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Answer:

t  =  1,28 s

Explanation: This problem is a projectile motion problem.

V₀ₓ = V₀ * cosθ

Vₓ  = constant all the way

Vₓ = V₀ₓ

tanθ  = Vyi/Vxi            that means in any point of the trajectory

tanθ  = 6 / 60         ( just before touching the ground )

tanθ  =  0,1       then arctan 0,1  ≈ 6⁰

sin 6⁰  =  0,1045

cos 6⁰ = 0,9945

V₀ₓ = V₀ * cosθ       ⇒  V₀  =  V₀ₓ / cosθ     ⇒  V₀  = 60 / 0,9945

V₀ = 60,33 m/s

V₀y = V₀  *  sin θ   ⇒   V₀y =  60,33 * 0,1045    ⇒  V₀y =  6,30 m/s

Vy = V₀y  - g * t

At  maximum y  Vy = 0    ( the middle of the trajectory)

g*tm = V₀y       ⇒    tm= V₀y / g

tm =  6,30 / 9,8

tm =  0,64 s       ( time to reach maximum y )

Then the time of fligh is twice 0,64 s

t   = 0,64 * 2

t  =  1,28 s

Answer:

Because they could help you move on better with your strategy and ultimately get you better scores on tests  

Answer:

Through feedback, teachers can provide the students with suggestions for development, learning strategies and corrections for errors. The importance of constructive feedback allows for many positive opportunities. This component also enhances a student's self-efficacy and provides an avenue for motivation.

F = ma

= 50kg × 2.5 m/s²

= 125 N

Answer : 125N

Explanation :

F = Force (N)

m = mass (kg)

a = acceleration (m/s²)

Answer:

Him

Explanation:

He will push less but more and he will use more energy

Answer:

Rubbing Alcohol

Explanation:

Answer:

The linear speed of the car is approximately 27.30 m/s

Explanation:

The question parameters are;

The mass of the person on the rollercoaster, m = 57.0 kg

The radius of the rollercoaster track, r = 42.7 m

The normal force felt by the person, F = 995 N

The centripetal force acting on the person keep the circular motion is given by the following equation;

[tex]Centripetal \, force \ F_c = \dfrac{m \times v^2}{r}[/tex]

Where;

v = The linear velocity of motion = The linear speed of the car

The centrifugal force, F, is the force normal force felt by the person and is equal to the centripetal force, therefore, we have;

[tex]Centripetal \, force \ F_c = Centrifugal \, force \ F = \dfrac{m \times v^2}{r}[/tex]

From which we have;

[tex]F = 995 = \dfrac{57 \times v^2}{42.7}[/tex]

[tex]\therefore v = \sqrt{\dfrac{995 \times 42.7}{57} } \approx 745.38[/tex]

The linear speed of the car = v ≈ 27.30 m/s

The angular speed of the car, ω = v/r ≈ 27.30/42.7 ≈ 0.639 rad/s

Answer: 18.1 m/s

Explanation:

Answer:

I believe this represents Newton's first law of motion. Any object in motion will continue to move until a force stops it, be it friction or a physical object.