1. How much work is done in lifting an 8-kg box
from the floor to a height of 2m above the
floor?

Answers

Answer 1

Answer:

156.8 Joules

Explanation:

Work = Force x Displacement

Displacement = 2m

Force (force of gravity) = mass x acceleration due to gravity =  8Kg x 9.8m/s^2

= 78.4N

Work = FxD

Work = 78.4 N x 2m

Work = 156.8 N·m  OR 156.8 Joules

Answer 2

The amount of work done in lifting this box is equal to 156.8 Joules.

Given the following data:

Mass = 8 kilograms.Displacement = 2 meters.

Scientific data:

Acceleration due to gravity = 9.8 [tex]m/s^2[/tex]

To calculate the amount of work that is done in lifting this box:

How to calculate work done.

Mathematically, the work done by a person is calculated by using this formula:

[tex]Work\;done = Fd = mgd[/tex]

Where:

F is the force.d is the displacement.m is the mass.

Substituting the given parameters into the formula, we have;

[tex]Work\;done = 8 \times 9.8 \times 2[/tex]

Work done = 156.8 Joules.

Read more on work done here: https://brainly.com/question/25573309


Related Questions

Fig. 2.1 shows a train
Fig. 2.1
The total mass of the train and its passengers is 750000kg. The train is travelling at a speed of 84m/s.
The driver applies the brakes and the train takes 80s to slow down to a speed of 42m/s.
(a) Calculate the impulse applied to the train as it slows down,
impulse =
[3]
(b) Calculate the average resultant force applied to the train as it slows down,
force =
(2)

Answers

Answer:

[tex]\mathrm{(a)\:}32,000,000\:\mathrm{Ns},\\\mathrm{(b)\:}390,000\:\mathrm{N}[/tex]

Explanation:

The impulse-momentum theorem states the impulse on an object is equal to the change in momentum of that object. Momentum is given by [tex]p=mv[/tex]. Since mass is constant, the train's change in momentum is:

[tex]\Delta p=m\Delta v=750,000\cdot42=31,500,000=\fbox{$32,000,000\:\mathrm{Ns}$}[/tex](two significant figures).

Impulse is also given as [tex]\Delta p = F\Delta t[/tex], where [tex]F[/tex] is the average force applied and [tex]\Delta t[/tex] is change in time. Since [tex]t[/tex] is given as [tex]80\mathrm{s}[/tex], we have the following equation:

[tex]F\Delta t=\Delta p\\\\F=\frac{\Delta p}{\Delta t},\\\\F=\frac{31,500,000}{80},\\\\F=393,750=\fbox{$390,000\:\mathrm{N}$}[/tex](two significant figures).

Please help i will give brainliest

Answers

Answer:

Answers below--

Explanation:

1. F/Force

2.H/Contact force

3.A/Non-contact force

4.C/electric force

5.D/gravity

6.I(i)/magnetic force

7.J/kilogram

8.G/newton

9.B/friction

10.E/lubricant

A horizontal pole is attached to the side of a building. There is a pivot P at the wall and a chain is connected from the end of the pole to a point higher up the wall. There is a tension force F in the chain. What is the moment of the force F about the pivot P?

Answers

Answer:

Fscos63

Explanation:

Given that a horizontal pole is attached to the side of a building. There is a pivot P at the wall and a chain is connected from the end of the pole to a point higher up the wall. There is a tension force F in the chain. What is the moment of the force F about the pivot P?

Taking the moment from the pivot point P, that means the moment at point p = 0

Then, if we consider the weight mg of the pole, according to the principle of equilibrium : sum of the upward forces equal to the sum of the downward forces.

Therefore, mg = Fsinø ....... (1)

Also, taking moment at point P

Let the length of the pole = s

The length of the weight of the pole = 1/2 S

Fscosø = mgs/2

The distance s will cancel out

2Fcosø = mg ...... (3)

Substitute mg in equation 1 into equation 3

2fcosø = fsinø

F will cancel out

Tanø = 2

Ø = tan^-1(2)

Ø = 63.4 degree

The moment of force F about pivot point P will be

Moment = force × distance

Moment = Fcos63 × S

Moment = Fscos63

A car of mass 1000 kg is travelling at 10 m/s. What is its kinetic energy?

Answers

Answer:

50,000

Explanation:

kinetic energy=1\2×mv^2

=1\2×1000kg×10×10

=50000

How many moons are in our solar system?

Answers

200 moons bro bro!!!!

A lift travelling up to the top floor of the Empire State building with a mass of 4200kg and a kinetic energy of 4116J. Find the velocity

Answers

Answer:

1.4 m/s

Explanation:

The velocity can be found by using the formula

[tex]v = \sqrt{ \frac{2k}{m} } \\ [/tex]

k is the kinetic energy

m is the mass

From the question we have

[tex]v = \sqrt{ \frac{2 \times 4116}{4200} } \\ = 1.4[/tex]

We have the final answer as

1.4 m/s

Hope this helps you

Answer:

The speed of the lift is 1.4 m/s

Explanation:

Kinetic Energy

Is the type of energy of an object due to its motion. It's proportional to the square of the speed and the mass.

The equation for the kinetic energy is:

[tex]\displaystyle K=\frac{1}{2}mv^2[/tex]

Where:

m = mass of the object

v = speed at which the object moves

The kinetic energy is expressed in Joules (J)

It's given the mass of the lift as m=4,200 kg and its kinetic energy K=4,116 J. To calculate the speed (magnitude of velocity), we solve the formula for v as follows:

[tex]\displaystyle v=\sqrt{\frac{2k}{m}}[/tex]

[tex]\displaystyle v=\sqrt{\frac{2*4,116}{4,200}}[/tex]

[tex]\displaystyle v=\sqrt{1.96}[/tex]

v = 1.4 m/s

The speed of the lift is 1.4 m/s

[04.04] Which best describes the current atomic theory? ​

Answers

Atoms are composed of electrons in different clouds around a positive nucleus.

The driver of a 1.5 x 103 kg car is traveling east at 10 m/s and increases its speed to 30 m/s east over 15 seconds. What was the change in momentum of the car? Kgm/s

Answers

Answer:

30,000kgm/s

Explanation:

Change in momentum is expressed as;

Change in momentum = mass × change in velocity

∆M = m∆v

Mass m = 1.5×10³kg = 1500kg

∆v = 30-10 =20m/s

Substitute into the formula

Change in momentum = 1500(20)

Change in momentum = 30,000kgm/s

A boat traveling across a river has a resultant velocity of 10 km/h and travels 34 degrees with respect to the shore. A) What is the boats velocity in m/s?
B) What is the velocity of the river in m/s?

Answers

Answer:

a) 1.55 m/s

b) 2.3 m/s

Explanation:

We know that the boat travels across the river, if we define the river as the x-axis, then the velocity of the boat is only on the y-axis.

Then we can write the velocity of the boat in still water as:

S = (0, B)

Now, when the boat is on the river, the velocity of the boat will be equal to the velocity of the boat in still water plus the velocity of the river.

The velocity of the river is:

v = (R, 0).

Then the velocity of the boat in that river is:

V' = (0, B) + (R, 0) = (R, B)

Now, we know that the velocity of the boat is 10km/h, and it travels at an angle of 34° with respect to the shore.

We can use the Pythagoreans theorem to write the components of this velocity as:

x-axis component = 10km/h*cos(34°) = 8.29 km/h

y-axis component = 10km/h*sin(34°) =  5.59 km/h

Then the velocity of the boat can be written in components as:

velocity = ( 8.29 km/h,  5.59 km/h)

And we knew that the velocity of the boat was written as  (R, B)

Then we must have:

R = 8.29 km/h

B = 5.59 km/h

a) The speed of the boat in m/s:

We know that the speed of the boat is 5.59 km/h.

First, we know that:

1km = 1000m, then:

5.59 km/h = 5.59*(1000m)h = 5,590 m/h

And we know that:

1h = 3600s

Then we can write:

5,590 m/h = 5,590 m/(3600s) = 1.55 m/s

b) The speed of the river in m/s:

We know that the speed of the river is 8.29 km/h

Using the same reasoning as above, we can do the change of units as follows:

8.29 km/h = 8.29 (1000m)/(3600s) = 2.3 m/s

Henry designs an experiment to find out why plants without flowers tend to be wind-pollinated and not animal-pollinated. He takes samples from a variety of plants and studies them in the field. He finds that the evidence supports his hypothesis. Which of these was the hypothesis Henry was testing? Choose the correct answer. Nonflowering plants make less pollen than flowering plants. Nonflowering plants lack the structures to attract animal pollinators. Nonflowering plants grow close to the ground and capture fewer pollinators. Nonflowering plants grow close to the ground because they have no pollen grains.

Answers

Answer:

option 2

Explanation:

you are very welcom

If Minnie the Mouse starts moving at 2m/s and increases her velocity to 4m/s because she is being chased, what is heracceleration if the time is 2 seconds?

Answers

Answer:

1m/s²

Explanation:

Given parameters:

Initial velocity  = 2m/s

Final velocity  = 4m/s

Time of chase  = 2s

Unknown:

Acceleration = ?

Solution:

Acceleration is the rate of change of velocity with time;

 A = [tex]\frac{v - u }{t}[/tex]  

A is the acceleration

v is the final velocity

u is the initial velocity

t is the time taken

      A  = [tex]\frac{4 - 2}{2}[/tex]   = 1m/s²

Marina walked 2km in half an hour, what was her average speed during her walk?

Answers

Answer:

4km/hr

Explanation:

A ball is thrown with 50J of kinetic energy, it hits a target which moves with 30J of kinetic energy, how much energy goes to the thermal store of the surroundings?

Answers

Answer:

The energy that will go will for thermal store of the surroundings is 20 J.

Explanation:

Given;

kinetic of the thrown ball, K.E₁ = 50 J

kinetic energy used to move the target, K.E₂ = 30 J

The excess energy that will go will for thermal store of the surroundings;

ΔK.E = K.E₁ - K.E₂

ΔK.E = 50J - 30J

ΔK.E = 20 J

Therefore, the energy that will go will for thermal store of the surroundings is 20 J.

A professional golfer walks at an at an average rate of 4.20 meters per second on the golf course. The amount of time required for her to walk from the tee to the green 622 meters away is

Answers

Answer:

T try d add b CD c

Explanation:

Cdgffd

2200 kg semi truck driving down the highway has lost control. The truck rolls across the median and into oncoming traffic. The truck collides with a 2000 kg car that is traveling north at 45 m/s. The two vehicles stick together creating a single wreck that travels south at 15 m/s. what was the initial speed and direction of the semi truck?

Answers

Answer:

The semi truck travels at an initial speed of 69.545 meters per second downwards.

Explanation:

In this exercise we see a case of an entirely inellastic collision between the semi truck and the car, which can be described by the following equation derived from Principle of Linear Momentum Conservation: (We assume that velocity oriented northwards is positive)

[tex]m_{S}\cdot v_{S}+m_{C}\cdot v_{C} = (m_{S}+m_{C})\cdot v[/tex] (1)

Where:

[tex]m_{S}[/tex], [tex]m_{C}[/tex] - Masses of the semi truck and the car, measured in kilograms.

[tex]v_{S}[/tex], [tex]v_{C}[/tex] - Initial velocities of the semi truck and the car, measured in meters per second.

[tex]v[/tex] - Final speed of the system after collision, measured in meters per second.

If we know that [tex]m_{S} = 2200\,kg[/tex], [tex]m_{C} = 2000\,kg[/tex], [tex]v_{C} = 45\,\frac{m}{s}[/tex] and [tex]v = -15\,\frac{m}{s}[/tex], then the initial velocity of the semi truck is:

[tex]m_{S}\cdot v_{S} = (m_{S}+m_{C})\cdot v -m_{C}\cdot v_{C}[/tex]

[tex]v_{S} = \frac{(m_{S}+m_{C})\cdot v - m_{C}\cdot v_{C}}{m_{S}}[/tex]

[tex]v_{S} = \left(1+\frac{m_{C}}{m_{S}} \right)\cdot v - \frac{m_{C}}{m_{S}} \cdot v_{C}[/tex]

[tex]v_{S} = v +\frac{m_{C}}{m_{S}}\cdot (v-v_{C})[/tex]

[tex]v_{S} = -15\,\frac{m}{s}+\left(\frac{2000\,kg}{2200\,kg} \right) \cdot \left(-15\,\frac{m}{s}-45\,\frac{m}{s} \right)[/tex]

[tex]v_{S} = -69.545\,\frac{m}{s}[/tex]  

The semi truck travels at an initial speed of 69.545 meters per second downwards.

Margaret Mary, Doug , and Kako are at a local amusement park. They see an attraction called the Giant Slide, which is simply a very long and high inclined plane. Visitors at the amusement park climb a long flight of stairs to the top of the 27inclined plane and are given canvas sacks. They sit on the sacks and slide down the plane 70m long. At the time when the three friends walked past the slide, a 135-kg man and a 20-kg boy are each at the top preparing to slide down. "I wonder how much less time it will take the man to slide down than it will take the boy," said Margaret Mary. "I think the boy will take less time," said Doug. "You're both wrong,"said Kako. "They will reach the bottom at the same time."

Answers

The question is incomplete. The compete question is :

Margaret Mary, Doug , and Kako are at a local amusement park. They see an attraction called the Giant Slide, which is simply a very long and high inclined plane. Visitors at the amusement park climb a long flight of stairs to the top of the 27inclined plane and are given canvas sacks. They sit on the sacks and slide down the plane 70m long. At the time when the three friends walked past the slide, a 135-kg man and a 20-kg boy are each at the top preparing to slide down. "I wonder how much less time it will take the man to slide down than it will take the boy," said Margaret Mary. "I think the boy will take less time," said Doug. "You're both wrong,"said Kako. "They will reach the bottom at the same time."

If the man and the boy do not take the same amount of time to reach the bottom of the slide, calculate how many seconds of difference there will between the two times.

Solution :

From body sliding down an incline plane, the acceleration is given by, [tex]$a = g \sin \theta$[/tex]

Since the body slides from rest, the initial velocity is, u = 0

Now the equation of motion, we have

        v= u + at

or     v = 0 +at

or      v = at

or     [tex]$t=\frac{v}{a}$[/tex] ............(1)

again we have, [tex]$v^2 -u^2 =2as $[/tex]

                         or [tex]$v = \sqrt{2s g \sin \theta} $[/tex]

Then from equation (1), we have

[tex]$t=\frac{\sqrt{2sg \sin \theta}}{g \sin \theta}$[/tex]

Thus this means that the time of sliding down an inclined plane does not depend on the mass of the body that slides.

Therefore, Kako is correct.

Since the time taken to slide an inclined plane is same for both the man and the boy, there is no difference between their time of sliding.

A wave has frequency of 50 Hz and a wavelength of 10 m. What is the speed of the wave? Group of answer choices

Answers

Explanation:

hehshehebdbajahwwdszsjshshs shsbw

Help, please! Thank you for your kind gesture

Answers

Answer:

The last option.

Explanation:

Since you are going down, the gravitational potential energy would go down too. Thus, the gravitational potential energy decreases.

Since the gravitational potential energy is converted to kinetic energy when you move down, there is an increase in kinetic energy.

Answer:

The fourth option

Explanation:

Metals are good conductors of heat because .

Answers

Answer:

They have the highest melting point so that mean that the temperature and the are a conductive to electricity.

Explanation:

Help Please! 5 questions for 25 points? seems fair? Thank you!

Answers

Answer:

1. where the skater turns and goes back in the opposite direction- point w

2. gravitational force of the object

3. point a

4. the bar representing sphere 4 should be twice as tall as the bar representing sphere 2

5. B; its mass is smaller (?)

yolo

Answer:

ABCDEFGHIJKLMNOPQRSTUVWXYZ

Explanation:

A wave that can travel through empty space?


A. electromagnetic wave
B. mechanical wave
C. compressional wave
D. transverse wave

Answers

Answer: B. Mechanical Waves

Explanation:

B hope this helps (I can be wrong)

You blow up a balloon but don't tie it. When you let it go, it flies around the room.
Which of Newton's Laws does the scenario describe?
1st Law
2nd Law
3rd Law

Answers

Answer:

3rd law beacuse there a flies

A construction worker pushes a wheelbarrow with a total mass of 50.0 kg. What is the acceleration of the wheelbarrow if the net force on it is 75N? For physical science

Answers

Answer:

1.5m/s²

Explanation:

Given parameters:

Mass of the wheelbarrow = 50kg

Net force applied  = 75N

Unknown:

Acceleration of the barrow = ?

Solution:

From Newton's second law of motion, we know that:

       Force  = mass x acceleration

 Now insert the parameters and find the acceleration

       75  = 50 x acceleration

      Acceleration  = 1.5m/s²

Why do we charge a capacitor under a DC voltage source only?

Answers

Capacitors are essentially two plates that are mounted next to each other, with a gap between them so that the plates don't touch. Direct current can't jump the gap between plates, because it would take a massive amount of voltage to force the electron to jump the gap between plates. The electrons hit the plate and stop. Alternating current, on the other hand, is moving the electrons back and forth in place -- so the plate on one side of the capacitor is constantly having electrons pushed in and then pulled back out. This motion creates a small electric field which induces the same alternating current in the other plate, because electric fields can jump the gap between plates. Therefore it is possible with ac supply only to make capcitor work.

If a 1000 kg car is traveling at 3
meters per second, what is its
kinetic energy?

Answers

Kinetic energy:
KE= .5 mv^2
KE = .5 * 1000 kg * 3 m’s^2
KE = 4500 kg m^2/s^2
KE = 4500 Joules

The image shows landforms in Monument Valley, Utah.

Which correctly lists the three features shown in the photo?

folds, strike-slip faults, and anticlines
anticlines, synclines, and folds
synclines, normal faults, and strike-slip faults
normal faults, folds, and anticlines

Answers

The correctly lists the three features shown in the photo is folds, strike-slip faults, and anticlines.

What is the difference between folds and failures?

Modern folds are those that emerged recently (on the scale of geological periods), that is, in the Tertiary Period (between 65 million and 2.5 million years ago). Faults are geological structures that originate from vertical (top-down) or inclined internal forces.

The transcurrent fault – also called horizontal fault – occurs when there is displacement in the horizontal plane between the two blocks, being more common in zones where two tectonic plates meet, when these also move horizontally.

See more about transcurrent fault at brainly.com/question/2387953

#SPJ2

Answer: folds, strike-slip faults, and anticlines. (A)

Explanation: Got it right on my exam on Edge.

Estimate the volume of each ball. Use the formula

where V is the volume and r is the radius. Record the volumes in Table A of your Student Guide.
What is the estimated volume of the table tennis ball?
cm3
What is the estimated volume of the golf ball?
cm3

Answers

The given question is incomplete. The complete question is:

Estimate the volume of each ball. Use the formula [tex]v=\frac{4\pi\times r^3}{3}[/tex] where v is the volume and r is the radius. record the volume in table A of your student guide. The radius of the tennis ball is 2.1 cm and the radius of thr golf ball is 2.0 cm. What is the estimated volume of the table tennis ball in [tex]cm^3 [/tex] What is the estimated volume of the golf ball in

Answer: Volume of the tennis ball is [tex]38.8cm^3[/tex] and  Volume of the golf ball is [tex]33.5cm^3[/tex]

Explanation:

We have to find the Volume of tennis ball and golf ball by using the formula [tex]v=\frac{4\pi\times r^3}{3}[/tex]

Radius of the tennis ball = 2.1 cm

Radius  of the golf ball =2.0 cm.

Putting the value of radius in the formula , we get:

Volume of the tennis ball =  [tex]\frac{4\times 3.14\times (2.1cm)^3}{3} =38.8cm^3[/tex]

Volume of the golf ball =   [tex]\frac{4\times 3.14\times (2.0cm)^3}{3} =33.5cm^3[/tex]

Volume of the tennis ball is [tex]38.8cm^3[/tex] and  Volume of the golf ball is [tex]33.5cm^3[/tex]

it's  38.8 and 33.5 hope this helps

Two billiard balls of equal mass collide. Ball 1 is initially moving at 0.43 m/s to the left, and ball 2 is initially at rest. Which of the following sets of final velocities does not describe an inelastic collision between the balls?


A. Ball 1 at 0.12 m/s left, Ball 2 at 0.31 m/s left

B. Ball 1 at 0.21 m/s left, Ball 2 at 0.22 m/s left

C. Ball 1 at 0.10 m/s left, ball 2 at 0.33 m/s left

D. Ball 1 at rest, ball 2 at 0.43 m/s left

Answers

The answer should be (B)

Answer: B

"Ball 1 at 0.21 m/s left, Ball 2 at 0.22 m/s left"

How high did a worker lift a 25 kg bag of sand if it now has 2940 of gravitational potential energy

Answers

Answer:

12 m

Explanation:

From the question given above, the following data were obtained:

Mass (m) of bag = 25 kg

Potential energy (PE) = 2940 J

Height (h) =?

Objects carried to a particular height will always experience an acceleration due to gravity of 9.8 m/s².

With the above in mind, we can obtain the height to which the load is lifted to as shown below:

Mass (m) of bag = 25 kg

Potential energy (PE) = 2940 J

Acceleration due to gravity (g) = 9.8 m/s².

Height (h) =?

PE = mgh

2940 = 25 × 9.8 × h

2940 = 245 × h

Divide both side by 245

h = 2940 / 245

h = 12 m

Therefore, the worker lifts the load to a height of 12 m.

h m u i m he ll a b o r e d

Answers

Answer:

KITTEEENNSSSSS last one is what i got for critsmas KlikBot Hexagon Special Pack

Explanation:

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