A builder drops a brick from a height of 15 m above the ground. The gravitational field strength g is 10 N/ kg. What is the speed of the brick as it hits the ground?

Answers

Answer 1

The speed of the brick dropped by the builder as it hits the ground is 17.32m/s.

Given the data in the question;

Since the brick was initially at rest before it was dropped,

Initial Velocity; [tex]u = 0[/tex]Height from which it has dropped; [tex]h = 15m[/tex]Gravitational field strength; [tex]g = 10N/kg = 10 \frac{kg.m/s^2}{kg} = 10m/s^2[/tex]

Final speed of brick as it hits the ground; [tex]v = \ ?[/tex]

Velocity

velocity is simply the same as the speed at which a particle or object moves. It is the rate of change of position of an object or particle with respect to time. As expressed in the Third Equation of Motion:

[tex]v^2 = u^2 + 2gh[/tex]

Where v is final velocity, u is initial velocity, h is its height or distance from ground and g is gravitational field strength.

To determine the speed of the brick as it hits the ground, we substitute our giving values into the expression above.

[tex]v^2 = u^2 + 2gh\\\\v^2 = 0 + ( 2\ *\ 10m/s^2\ *\ 15m)\\\\v^2 = 300m^2/s^2\\\\v = \sqrt{300m^2/s^2}\\ \\v = 17.32m/s[/tex]

Therefore, the speed of the brick dropped by the builder as it hits the ground is 17.32m/s.

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Related Questions

A laser beam is used to levitate a metal disk against the force of earth's gravity.
(a) derive an equation giving the required intensity of light, i, in terms of the mass m of the disk, the gravitational acceleration g, the speed of light c, and the cross-sectional area of the disk a. assume the disk is perfectly reflecting and the beam is directed perpendicular to the disk. (do not substitute numerical values; use variables only.)
i =
(b) if the disk has mass 3.89 g and radius 2.40 cm, find the necessary light intensity.
(c) give two reasons why using light pressure as propulsion near earth's surface is impractical.

Answers

The necessary light intensity of the disk if the disk has mass 3.89 g and radius 2.40 cm is 6.483 x 10^12cd.

Calculations and Parameters:

a. Given that:

i= intensity of light m= mass of disk g= gravitational acceleration c= speed of light a= cross-sectional area of the disk

I = P/A

= Force x Speed/Area

Gravitational force, F= GM1M2/r^2

F= ma, F= mg

I= mg x c/q

That is,

i= mass x gravitational acceleration x speed/area

b.

Mass= 3.89g

Radius, r= 2.40cm

i=?

i= mg x c/a

Speed of light= 3.0 x 10^8 m/s

Area, a= /pi r^2

= 3.142 x (0.024)^2

= 3.142 x 0.000576

= 0.0018m^2.

i= 3.89 x 10 x 3.0 x 10^8/0.0018

i= 6.483 x 10^12cd.

c. Light has no mass, therefore, it lacks momentum and cannot exert pressure for propulsion of materials.

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Use F = 1/T as your basis:
10. A stroboscope is set to flash every 8.00×10−5s. What is the frequency of the flashes?

The answer is 12,500 Hz but please show your work.

Answers

Time=T=8×10^-5s

Now

[tex]\\ \rm\rightarrowtail \nu=\dfrac{1}{T}[/tex]

[tex]\\ \rm\rightarrowtail \nu=\dfrac{1}{8\times 10^{-5}}[/tex]

[tex]\\ \rm\rightarrowtail \nu=0.125(10^5)[/tex]

[tex]\\ \rm\rightarrowtail \nu=12500s^{-1}[/tex]

[tex]\\ \rm\rightarrowtail \nu=12500Hz[/tex]

A car initially travels west with a kinetic energy of 10 J. Then it travels east at three times its original speed. What is its kinetic energy when it is traveling east

Answers

KE₁ = 1/2mv²

10 J = 1/2mv²

KE₂ = 1/2m(3v)²

KE₂ = 1/2mv².9

KE₂ = 10 . 9 = 90 J

Which terrestrial planet exhibits retrograde rotation?.

Answers

Answer:

Planets that are farther from the sun than the earth (all but Mercury and Venus) will exhibit retrograde motion.

If the position of the planet is observed relative to the background stars, the planet will appear to move backward relative to the stars when the earth is moving in an Eastward direction faster than the planet, and the planet appears to move backwards relative to the stars

(The planet will be on the side of the earth that is opposite that of the sun)

Given the velocity v= ds dt and the initial position of a body moving along a coordinate line, find the body's position at time t

Answers

For  the​ body's position at time t  is mathematically given as

s(t)=4.9t^2+5t+16

What is the​ body's position at time t

Generally, the equation for the velocity is mathematically given as

v=ds/dt

v=9.8t+5 as velocity

s=4.9t^2+5t+c

s(0)=16

16=c

s(t)=4.9t^2+5t+16

In conclusion the​ body's position at time t

s(t)=4.9t^2+5t+16

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The body position at the given time t is s = 4.9t² + 5t + 16 if the velocity v= ds/dt and the initial position of a body moving along a coordinate line.

What is the distance?

A numerical representation of the distance between two items or locations is called distance. A physical length or an approximation based on other considerations in physics or common usage can be referred to as distance.

We have:

[tex]\rm v = \frac{ds}{dt}[/tex]

[tex]\rm v = 9.8t+5[/tex]  is the velocity

[tex]\rm s = 4.9t^2+5t+c[/tex] is the speed

At t = 0 s(0) = 16

16 = c

[tex]\rm s = 4.9t^2+5t+16[/tex]

Thus, the body position at the given time t is s = 4.9t² + 5t + 16 if the velocity v= ds/dt and the initial position of a body moving along a coordinate line.

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An object moving in the xy-plane is subjected to the force f⃗ =(2xyı^ 3yȷ^)n, where x and y are in m

Answers

The magnitude of the work done by force experience by the object is (2a²b + 3b²)J.

Work done by the force experienced  by the object

The magnitude of the work done by force experience by the object is calculated as follows;

W = f.d

where;

F is the applied force (2xyi + 3yj), where x and y are in metersd is the displacement of the object = (a, b)

The work done by the force is determined from the dot product of the force and the displacement of the object.

F = (2xyi + 3yj).(a + b)

W = (2abi + 3bj).(ai + bj)

W = (2a²b + 3b²)J

Thus, the magnitude of the work done by force experience by the object is (2a²b + 3b²)J.

The complete question is below:

The particle moves from the origin to the point with coordinates (a, b) by moving first along the x-axis to (a, 0), then parallel to the y-axis.

How much work does the force do?

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The total work done  for an object moving in the xy-plane is subjected to the force f⃗ =(2xyı^ 3yȷ^)n, where x and y are in m is 3ab N.

What is work done?

Work done is the force applied on a body to move it over a distance. Work done for inclined plane can be given as,

[tex]W=F\times d[/tex]

Here (F) is the magnitude of force and (d) is the distance traveled.

An object moving in the xy-plane is subjected to the force

[tex]\vec f =(2xy\hat i +3y\hat j)[/tex]

Here, x and y are in meter.

The particle moves from the origin to the point with coordinates (a, b) by moving first along the x-axis to (a, 0), then parallel to the y-axis.

(a) How much work does the force do?

For the first part, the particle moves along x-axis. It moves zero along x-axis. Thus, the force, as y=0.

[tex]W_1=\int\limits^a_0 {2xy\hat i} \, dx =0\\[/tex]

Now, when the object moves along y-axis,

[tex]W_2=\int\limits^a_0 {3y\hat j} \, dx \\W_2=3\int\limits^b_0 {y\hat j} \, dx\\W_2=3y(a-0)\\W_2=3ba\\W_2=3ab[/tex]

Total work done,

[tex]W=0+3ab\\W=3ab\rm\; N[/tex]

Thus, the total work done  for an object moving in the xy-plane is subjected to the force f⃗ =(2xyı^ 3yȷ^)n, where x and y are in m is 3ab N.

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How are physical descriptions and physical properties similar?

Answers

Answer:

A physical property and physical description are similar because the changes in a physical property of a system can be used to describe its changes between momentary states.

A physical property is is defined as any property that is measurable, and also  whose value describes a state of a physical system.

Examples of physical properties include;

density,

hardness,

melting and boiling points, and

thermal conductivity

A physical description is observed physical properties usually represented by a specific class, compound or elements.

Both physical property and physical description are similar because the changes in a physical property of a system can be used to describe its changes between momentary states.

Answer:

A physical property is a characteristic of a substance that can be observed or measured without changing the identity of the substance. Physical properties include color, density, hardness, and melting and boiling points. A chemical property describes the ability of a substance to undergo a specific chemical change.

You are part of a police unit that has found a powder in a suspect's home. You think it might be a new drug called XYZ. XYZ is an ionic compound that dissolves in water. However, what you think might be a drug may just be salt. Unfortunately there seems to be iron fillings and sand mixed in with the white powder. Your job is to isolate the white powder before sending it to the police lab to be tested to determine if it is salt or XYZ. Give step by step directions on exactly how you will separate your mixture of white powder, iron fillings, and sand.

Answers

The steps in the separation include;

Use of magnetaddition of water and filtrationEvaporation

Separation techniques

Separation techniques has to do with how to obtain a substance in the presence of other substances. In this case, we have the substance XYZ mixed with iron filling and sand.

The separation process begins by using a magnet to remove all the iron fillings. Secondly, water is added and the substance XYZ dissolve in water since it is ionic. The sand can be separated form the solution by filtration.

Lastly, the solution is evaporated and the pure XYZ is obtained and sent to the police lab for analysis.

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Two wave pulses move toward each other along a rope. two small triangular crests moving toward each other. which diagram shows the resulting wave when they cross at point x? a straight line. a triangular crest. a rectangular crest. a triangular trough.

Answers

The triangular crest. shows the resulting wave when they cross at a point x. The meeting point of two waves is known as wave interference ia x.

What is wave pulse?

A wave pulse is a short, non-periodic wave that is formed by a single energy input rather than a continuous or repeated energy input.

Wave interference is the result of multiple waves interacting. There are two types of interference: constructive and destructive.

The relative displacement of the waves is the difference between the two. Wave beats are frequently caused by wave interference.

Hence the triangular crest. shows the resulting wave when they cross at a point x.

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Answer:

B

Explanation:

Got it right on edge

Which property of the water molecule causes two water molecules to be attracted to each other? (2 points)
Polar bonds between H and O atoms
Ionic bonding between water molecules
Hydrogen bonds between H atoms
Ionic bonding between O atoms

Answers

Answer:

hydrogen bonding between H atoms.

Explanation:

Brody drives 180 km in two hours. How fast is he travelling?
should be in km/hour)

Answers

Answer:

90 km/h

Explanation:

we just divide the distance by the time to get the speed.

How much energy does a pair of hair straighteners transfer every second

Answers

Answer:

It depends...

Explanation:

If you know how much watts the pair of hair straighteners use, you can use that as the energy every second. A normal flat iron for hair would be 300 watts, so we could say that it uses 300 jolts or watts of energy per second.

project: weather forcasting
Instructions
Click the links to open the resources below. These resources will help you complete the assignment. Once you have created your file(s) and are ready to upload your assignment, click the Add Files button below and select each file from your desktop or network folder. Upload each file separately.

Answers

B that is the correct answer

The inner planets are different from the outer planets mainly because they are:.

Answers

Answer:

The inner planets are closer to the Sun and are smaller and rockier. The outer planets are further away, larger and made up mostly of gas. The inner planets (in order of distance from the sun, closest to furthest) are Mercury, Venus , Earth and Mars.

Explanation:

Which describes the vector calculation giving the magnetic force on a charged particle moving through a magnetic field?.

Answers

Which describes the vector calculation giving the magnetic force on a charged particle moving through a magnetic field? It is the cross product of the velocity vector and the magnetic field vector, which gives a vector perpendicular to those vectors.

Find the kinetic energy k of the block at the moment labeled b. express your answer in terms of k and a.

Answers

The position of the object can be used to find the kinetic energy in terms of k and a.

What is kinetic energy?

The term kinetic energy refers to the energy of an object that is in motion. The question is incomplete hence the syetem is not shown and the value of the kinetic energy can not be found in terms of  k and a.

Hence, when the system is shown, we can look at the position of the system and use it to obtain the value of the kinetic energy in terms of k and a.

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Answer:

K = 3/8k(A)^2

Explanation: Potential Energy --> Conservation of Energy

Because block B is at A/2, U = 1/2k(A/2)^2 which equals U = 1/8k(A)^2.

Now that you have the equation for potential energy, you can find kinetic energy in terms of the spring constant (k) and amplitude (A).

K = 3/8 k A^2

A car initially travels at 10 m/s when passing the "acceleration line". The car then accelerates Q. at 8m/s2 until reaching a final velocity of 40 m/s. What is the car's displacement during the acceleration?
answer choices
3.75 m
93.75 m
100 m
1590 m​

Answers

[tex]\text{Given that,}\\\\\text{Initial velocity,}~ u = 10 ~ms^{-1}\\\\\text{Final velocity,}~ v = 40 ~ ms^{-1}\\\\\text{Acceleration,}~ a = 8 ~ ms^{-2}\\ \\\text{Time ,}~ t =?\\\\\text{Displacement, }~ s = ?\\\\\text{We know that,}\\\\a= \dfrac{v-u}{t}\\ \\\implies t = \dfrac{v-u}{a} = \dfrac{40-10}{8} = \dfrac{30}{8} = 3.75 ~sec \\\\s=\left(\dfrac{u+v}2\right)t=\left(\dfrac{10+40}2 \right)3.75 = \left(\dfrac{50}{2}\right)3.75 = 25 \times 3.75 = 93.75~m[/tex]

[tex]\text{Hence, the displacement of the car is 93.75 m}[/tex]

Suppose that a simple pendulum consists of a small 60.0 g bob at the end of a cord of negligible mass. If the angle 0 between the cord and the vertical is given by g - (0.0800 rad) cos[(4.43 rad/s) t 0], what are (u) the pendulum's length and (b) its maximum kinetic energy

Answers

Based on the mass of the bob and the angle between the cord and the vertical, the pendulum length is 0.50m.

The maximum kinetic energy can be found to be 9.42 x 10⁻⁴J.

What is the pendulum length?

This can be found as:

= g-force / w²

Solving gives:

= 9.8 / 4.43²

= 0.4998 m

= 0.50 m

What is the maximum kinetic energy?

This can be found as:

= 0.5 × m × w² × A²

Maximum kinetic energy is:

= 0.5 × 60 × 10⁻³ × (4.43 × 0.4998 x 0.08 rad)²

= 9.42 x 10⁻⁴J

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When do things move faster? Day or night?​

Answers

I believe most activity takes place during daylight hours.So the life move fast in day. If we talk about the -Sound. At night , the air is denser due to humidity (obviously nights are cooler). sound requires medium to travel and so DENSER the medium,FASTER the sound travels.

I believe at night because during the day i feel like more things are happening so thing may be slowed down

Hello people ~
The sound in the audible range is called
(a) ultrasonic sound
(b) sonic sound
(c) subonic sound
(d) light sound​

Answers

Answer:

Sonic sound

Human audible range is from 20Hz to 20000Hz or 20kHzAbove or beneath that range we can't hear .Bats can hear below it and dogs can hear above it

Which of the following statements about waves are true? Select all that apply.
O
Sound waves cannot travel through empty space.
Sound waves can travel through liquids.
Light waves are not true waves.
Light waves need matter in order to travel.
Waves can only move matter up and down or from side to side.

Answers

Answer:

Sound waves cannot travel through empty space

sound can travel through liqui

Sound waves cannot travel through empty space but can travel through liquids. Waves make the particles of matter up and down but do not along with them. The light waves are not true mechanical waves. Therefore, options (A), (B), (C), and (E) are correct.

What are sound waves?

Sound can transmit through liquids, gases, and plasma as longitudinal waves, also known as compression waves. It needs a medium to propagate so it can be propagated through solids as both longitudinal waves and transverse waves.

Longitudinal sound waves contain alternating pressure deviations causing compression and rarefaction, while transverse waves have waves of alternating shear stress perpendicular to the direction of propagation.

Waves can make matter move up and down or from side to side but do not carry along with them. Light waves are not considered true waves because they carry without the involvement of the motion of matter.

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What is the frequency of a photon with an energy of 4. 56 x 10^-19 j

Answers

Answer:

ν = E/h = 4.56x10-19 J / 6.626x10-34 Jsec-1

ν = 6.88x1014 s-1

Explanation:

The frequency of a photon with an energy of 4.56 x 10⁻¹⁹ J is 6.88×10¹⁴ s⁻¹.

What is a frequency?

The number of waves that travel through a particular point in a given length of time is described by frequency. So, if a wave takes half a second to pass, the frequency is 2 per second.

Given that the energy of the photon is 4.56 x 10⁻¹⁹ J. Therefore, the frequency of the photon can be written as,

[tex]\rm \gamma = \dfrac{E}{h} = \dfrac{4.56x10^{-19} J}{6.626 \times 10^{-34}\ Jsec^{-1}}\\\\\\\gamma = 6.88 \times 10^{14}\ s^{-1}[/tex]

Hence, the frequency of a photon with an energy of 4.56 x 10⁻¹⁹ J is 6.88×10¹⁴ s⁻¹.

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A hot tungsten filament emit electromagnetic radiation within

Answers

A hot tungsten filament emit electromagnetic radiation within the bulb because the tungsten is present within the bulb.

What temperature does a tungsten filament glow at?

Due to its high melting point, tungsten can be heated to 3000°C where it glows white hot providing very good brightness due to the presence of argon.

So we can conclude that a hot tungsten filament emit electromagnetic radiation within the bulb.

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Electromagnetic radiation is made up of electromagnetic field waves. A hot tungsten filament emits electromagnetic radiation in the presence of Argon.

What is electromagnetic radiation?

Electromagnetic radiation is made up of electromagnetic field waves that travel through space carrying electromagnetic radiant energy. Radio waves, microwaves, infrared, light, ultraviolet, X-rays, and gamma rays are all examples of electromagnetic waves.

When tungsten is heated to a temperature of around 3000 °C, the tungsten starts to emit lights. Tungsten when used in a bulb as a filament then because of its high melting point when electricity is passed through it, it starts to shine white-hot and provides extremely good brightness due to the presence of argon.

Hence, A hot tungsten filament emits electromagnetic radiation in the presence of Argon.

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A fish swimming at a constant speed of 0.5 m/s suddenly notices a shark
appear behind it. Five seconds later, the fish is swimming in the same
direction at a speed of 3.5 m/s. Calculate the fish's acceleration?


PLEASE HELP <33

Answers


t he fish's acceleration is 0.4m/s².
the acceleration of the fish is 0.4m/s squared

3. Barrett was working in his shop on a truck. Suddenly something exploded and sent his wrench flying across
the shop at 25m/s and it took the wrench 5 seconds to get from one side of the garage to the other. What wa
the distance Barrett's wrench traveled during the explosion?

Answers

Answer:

125 meters

Explanation:

we know that

v × t = d

v = 25

t = 5

so the distance should be 5 × 25

answer is 125 meters

meters/second?
A car accelerates from 4 meters/second to 16 meters/second in 4 seconds. The car's acceleration is what meters/second squared

Answers

Answer:

the acceleration of the car is 3 m/s².

Explanation:

Part B
At your sink, turn on your faucet slowly, until you have achieved a steady drip, drip, drip of lukewarm water. Make sure you can visually see and count the drips. Align the center of the bar of soap with the dripping water and set it down. Make sure the soap is in a sturdy location and does not move during the experiment. The soap represents a rock, and the dripping faucet represents precipitation.

While the soap is being weathered, calculate the number of drips that hit it in a minute. Do this by using your stopwatch to count the number of drips that occur in 10 seconds, and then multiply that number by 6 (because there are 60 seconds in a minute, 6 × 10 = 60). What is the number of drips hitting your bar of soap per minute?

Answers

The experiment was conducted in my toilet wash hand sink with a bar soap 30 centimeter away from the faucet, the number of drips record per minute is 120 drips

Control Experimentation

Data

Number of Drips Recorded = 20 drips per 10 secondsIn one minute(60 seconds), the number of drips recorded will be

Calculation for the number of drips per minute

= 20*6

= 120 drips

What is Control Experiment

Control  experiment are carried out to minimize the effects of variables other than the independent variable

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An apple weighing 1 N fall a distance of 1 m how much work is done on the Apple by the force of gravity

Answers

Explanation:

work = Force×distance

Force in this question is equal to the weight (force of gravity)

work = 1 × 1 = 1 J

Jole is the unit of work

How long does it take for jupiter to rotate on its axis.

Answers

Answer:

10 hours.

Every 10 hours, Jupiter will rotate at least once. It takes 12 years for Jupiter to make a revolution. This is because Jupiter is a gas, non-solid planet and also has a very large mass.

Answer: 10 Hours

Explanation:

Jupiter is the fastest spinning planet in the solar system


Extension Question
If the scale used to measure the mass of the unknown material maxes out at a
lower value than the actual mass of the material, then...
o the measured specific heat will be greater than the actual specific heat.
o the measured specific heat will be less than the actual specific heat.

Answers

The measured specific heat will be less than the actual specific heat if a lower value is gotten than the actual mass.

What is Specific heat capacity?

This is defined as the quantity of heat needed to raise a substance's temperature by 1 degree Celsius.

If a substance has a low specific heat capacity , it loses water easily which makes the mass when measured to be smaller than the actual value.

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