3) A 60. kg person is in an elevator. The elevator starts from rest and then accelerates upwards at 2.0 m/s^2 for 4.0 seconds. Calculate the work done by the normal force on the person. *

Answers

Answer 1

Answer:

WD = 960 J

Explanation:

WD = work done (J)

F = force (N)

s = displacement (m)

m = mass (kg) = 60

a = acceleration (m/s²) = 2

t = time (s) = 4

u = initial velocity (m/s) = 0

The formulas or equations that are relevant ate:

WD = F × s

F = m × a

s = u + at

We want to find WD, so we need to now the force and the displacement (or distance);

We calculate force, in Newtons, with the formula F = ma:

F = 60 × 2

F = 120 N

We also need displacement, which get with the formula s = u + at:

s = 0 + 2(4)

s = 8 m

Now we have F and s, we can calculate WD:

WD = 120 × 8

WD = 960 J

Methodology:

Starting with what you want to find, in this case WD, list the formula/s you could use;

Then, identify the information you need for the formula and whether or not you are given that information;

Next, list the formulas for the information you don't have and once again, identify whether the information you are given is sufficient to use those formulas;

Once you can calculate all necessary information, then proceed to calculate the values and finally, the answer;

I suggest also keeping a list of all the variables as I've done at the top of my working so it is clear for you to see and use.


Related Questions

An empty cylindrical barrel is open at one end and rolls without slipping straight down a hill. The barrel has a mass of 15.0 kg, a radius of 0.400 m, and a length of 0.800 m. The mass of the end of the barrel equals a fourth of the mass of its side, and the thickness of the barrel is negligible. The acceleration due to gravity is =9.80 m/s2.
What is the translational speed f of the barrel at the bottom of the hill if released from rest at a height of 33.0 m above the bottom?

Answers

Hi there!

We can use work and energy to solve this problem.

We know that:

Ei = Ef

Ei = Potential energy = mgh

Ef = Rotational kinetic + Translational kinetic = 1/2Iω² + 1/2mv²

The barrel is comprised of a hollow cylinder and disk-shaped bottom, so:

I (hollow cylinder) = mr²

I (disk) = 1/2mr²

Calculate the moment of inertias of each.

Since the mass on the base is one-fourth of its side:

x = mass of side

x + x/4 = 15

4x + x = 60

5x = 60

x = 12 kg

end mass = 3 kg

Solve for each moment of inertia:

Side: (12)(0.4²) = 1.92 Kgm²

Bottom: 1/2(3)(0.4²) = 0.24 Kgm²

Side + bottom = 2.16 Kgm²

We can now solve:

mgh = 1/2mv² + 1/2(2.16)v²/r²

(15)(9.8)(33) = 1/2(15)v² + 1/2(13.5)v²

4851 = 14.25v²

v = 18.45 m/s

A 1.1 kg ball drops vertically onto a floor, hitting with a speed of 23 m/s. It rebounds with an initial speed of 5.0 m/s. (a) What impulse acts on the ball during the contact

Answers

Hi there!

We know that:

I = Δp = m(vf - vi)

Plug in the given values. Remember to take into account direction ⇒ let the rebound velocity be positive and initial be negative.

I = 1.1(5 - (-23)) = 30.8 Ns

The car on this ramp starts from rest. When released, it
accelerates at a constant rate. It has an initial position of 12 cm
from the top of the ramp, and has an average velocity of 1.20 m/s
for a total of 1.80 s. Which is the correct final position of the car?

Answers

Answer:

Explanation:

s 0.12 + 1.20(1.80) = 2.28 m from the top.

An object is dropped from a vertical height of 1.89 m above the balcony level. What is the object’s speed when it is 2.20 m below the balcony level if 10.0% energy is lost due to the air resistance? Does it matter when to apply 10% loss before V calculations or after? [8.49m/s] [yes it does, 0.9Energy result in √0.9Velocity]

Answers

a.

The object's speed at 2.20 m below balcony level is 8.74 m/s

Let the balcony level be 0 m and the height above the balcony level be positive and height below the balcony level negative.

Using the principle of conservation of energy, the total energy at a vertical height of 1.89 m above the balcony level equals the total mechanical energy when the object is 2.20 m below the balcony level and

So, E = E'

U + K + f = U' + K' + f'

where U = initial potential energy at 1.89 m = mgh, K = initial kinetic energy at 1.89 m = 0 J(since it is released from rest), f = energy loss at 1.89 m = 0 J, U' = final potential energy at 2.20 m below balcony level = mgh', K = final kinetic energy at 2.20 m = 1/2mv², f' = energy loss at 1.89 m = 10%U = 0.10mgh(since 10% of the initial energy is lost).

So,

U + K + f = U' + K' + f'

mgh + 0 + 0 = mgh' + 1/2mv² + 0.10mgh

mgh = mgh' + 1/2mv² + 0.10mgh

Dividing through by m, we have

gh = gh' + 1/2v² + 0.10gh

So, gh -  0.10gh = gh' + 1/2v²

0.90gh = gh' + 1/2v²

1/2v² = 0.90gh - gh'

1/2v² = g(0.90h - h')

v² = 2g(0.90h - h')

Taking square-root of both sides, we have

v = √[2g(0.90h - h')]

where v = velocity of object at 2.20 m below balcony level, h = height above the balcony level = 1.89 m, h' = height below the balcony level = -2.20 m and  g = acceleration due to gravity = 9.8 m/s²

Substituting the values of the variables into the equation, we have

v = √[2g(0.90h - h')]

v = √[2 × 9.8 m/s²{0.90 × 1.89 m - (-2.20 m)}]

v = √[2 × 9.8 m/s²(1.701 m + 2.20 m)]

v = √[2 × 9.8 m/s²(3.901 m)]

v = √[76.4596 m²/s²]

v = 8.74 m/s

So, the object's speed at 2.20 m below balcony level is 8.74 m/s

b.

Yes it does matter when we apply 10% loss before V calculations

We need to apply the 10 % loss before V calculations because this would give us a proper value for V since the energy is lost before V is obtained.

So, yes it does matter when we apply 10% loss before V calculations

Learn more about speed of a falling object here:

https://brainly.com/question/18732868

A clothes dryer in a home draws a current of 10 amps when connected on a special 220-volts household circuit.what is the resistance of the dryer?

Answers

Answer:

22Ω

Explanation:

if    V ⇒ voltage

      I ⇒ current

      R ⇒ resistance

V = IR

220 = 10 x R

220 / 10 = R

22 = R

What happens when the object is placed at F? Explain
your answer.

Answers

Answer:

Sample Response: No image will be formed because the rays will not converge to or diverge from a common point.

Explanation:

A flywheel having constant angular acceleration requires 4.70 s to rotate through 164 rad . Its angular velocity at the end of this time is 101 rad/s . Find the angular velocity at the beginning of the 4.70 s interval. Find the angular acceleration of the flywheel.

Answers

Answer:

A) -31.2 rad/s

B) 28.1 rad/s^2

Explanation:

Objects 1 and 2 attract each other with a gravitational force of 179 units. If the distance separating objects 1 and 2 is changed to four times the original value (i.e., quadrupled), then the new gravitational force will be ______ units.

Answers

Explanation:

Fgravity = G*(mass1*mass2)/D²

G is the gravitational constant throughout the universe.

D is the distance between the 2 objects.

the distance is now quadrupled.

Fgravitynew = G*(mass1*mass2)/(4D)² =

= G*(mass1*mass2)/(16D²) =

= (G*(mass1*mass2)/D²) / 16 = Fgravity/16

the new gravitational force will be 179/16 = 11.1875 units

Someone with a force of 900 N does not float in a freshwater pool. To prevent them from sinking, 20 N must be applied in an upward fashion. What is their volume and average density?

Answers

Explanation:

The buoyant force [tex]F_B[/tex] is defined as

[tex]F_B = \rho_wgV[/tex]

where [tex]\rho_w[/tex] is the density of the displaced fluid (freshwater), g is the acceleration due to gravity and V is the volume of the submerged object. In the case of freshwater, its density is [tex]997\:\text{kg/m}^3.[/tex] Since the buoyant force is 20 N, we can solve for the volume of the displaced fluid:

[tex]F_B = \rho_wgV \Rightarrow V = \dfrac{F_B}{\rho_wg}[/tex]

Plugging in the values, we get

[tex]V = \dfrac{20\:\text{N}}{(997\:\text{kg/m}^3)(9.8\:\text{m/s}^2)}[/tex]

[tex]\:\:\:\:\:= 2.05×10^{-3}\:\text{m}^3[/tex]

Recall that the weight of an object in terms of its density and volume is given by

[tex]W = \rho gV[/tex]

Using the value for the volume above, we can solve for the density of the object as follows:

[tex]\rho = \dfrac{W}{gV} = \dfrac{900\:\text{N}}{(9.8\:\text{m/s}^2)(2.05×10^{-3}\:\text{m}^3)}[/tex]

[tex]\:\:\:\:\:= 44,798\:\text{kg/m}^3[/tex]

a man can jump 9meteres on the moon.how high can he jump on the earth.​

Answers

Answer:

You can jump 1.5 feet on Earth.

Explanation:

Because the moons gravity is weaker that earth so it would be easier to jump further on the moon.

All circuits include


a battery, wires, and a switch.


an energy source, a resistor, and a battery.


a battery, a light bulb, and a switch.


an energy source, a load, and wires.

Answers

Answer:

a battery, wires, and a switch.

Explanation:

All circuits include?

The control center of human body is * 1/1 heart
brain  
liver
  We have ________ sense organs * 1/1
6
4
5    
Which energy we get by burning of fuels * 1/1
Solar
Heat
  Light
  Sources of energy that can be used again and again will never run out * 1/1 Non renewable energy Renewable energy   Running water   What is called structure that build on rivers to get electricity * 1/1 Dam   Check dam Tunnel   Which nutrients protect us from diseases * 1/1 Carbohydrate Vitamin and Mineral   Protein   When is the best time of the day to water your lawn * 1/1 Early morning and late evening   Afternoon Night   Which of these ways to wash the car saves the most water? * 1/1 Wash it in the driveway with the garden hose Drive it into the lake Take it through a car wash that recycles water     Why do we keep food and vegetables in refrigerator? * 1/1​

Answers

The brain: the control center of the body.5. The sense organs — eyes, ears, tongue, skin, and nose — help to protect the body.Key Concept: When fuels are burned, the chemical energy that is released can be used to generate another form of energy, such as heat, light, motion, or electricity. A fuel is a substance that provides energy as a result of a chemical change.However, scientists are continually addressing these challenges, working to improve feasibility and reliability of renewable resources. Renewable resources include biomass energy (such as ethanol), hydropower, geothermal power, wind energy, and solar energy.Many dams are built for more than one purpose; for example, water in a single reservoir can be used for fishing, to generate hydroelectric power, and to support an irrigation system. Water-control structures of this type are often designated multipurpose dams.Antioxidants — such as vitamins C and E and carotenoids, which include beta-carotene, lycopene and lutein — help protect healthy cells from damage caused by free radicals.Water in the early morning – between 6 a.m. and 10 a.m. Midday watering leads to wasteful evaporation, while nighttime watering causes droplets to cling to grass overnight, increasing the chance of lawn diseases.Use a bucket instead of a continuous water flow from a hose. If you are using a hose, use one which has a spray handle that automatically shuts off the nozzle as you leave it. According to the Department of Environment, Maryland, USA, a 100 gallon car wash reduces to 30 gallons in such an arrangement.We refrigerate food to keep bacteria, yeasts, and molds from the favorable temperature they need to grow. The moisture-control available in many refrigerators also helps slow the deterioration of foods, so that two of the three favorable situations for microorganism growth are eliminated.

14 The radius of gyration of a body about an axis &ta
distance 6 cm from its centre of mass is 10 cm.
Then, its radius of gyration about a parallel axis
through its centre of mass will be
(a) 80 cm (b) 8 cm (c) 0.8 cm (d) 0.08 cm

Answers

Correct option is B 8 cm.

Let radius of gyration for the axis not passing through center of mass be r and that for the axis passing through the center of mass be k and the distance between the two parallel axes be a.

Parallel axes theorem gives:

[tex] {mr}^{2} = m( {k}^{2} + {a}^{2} ) \\ ⇒ {r}^{2} = {k}^{2} + a {}^{2} [/tex][tex]⇒k = \sqrt{ {10}^{2} - {6}^{2} } = 8cm.[/tex]

Thus, option B is the correct answer.

For the ballistic missile aimed to achieve the maximum range of 9500 km, what is the maximum altitude reached in the trajectory

Answers

Explanation:

The range R of a projectile is given the equation

[tex]R = \dfrac{v_0^2}{g}\sin{2\theta}[/tex]

The maximum range is achieved when [tex]\theta = 45°[/tex] so our equation reduces to

[tex]R_{max} = \dfrac{v_0^2}{g}[/tex]

We can solve for the initial velocity [tex]v_0[/tex] as follows:

[tex]v_0^2 = gR_{max} \Rightarrow v_0 = \sqrt{gR_{max}}[/tex]

or

[tex]v_0 = \sqrt{(9.8\:\text{m/s}^2)(9.5×10^6\:\text{m})}[/tex]

[tex]\:\:\:\:\:\:\:=9.6×10^3\:\text{m/s}[/tex]

To find the maximum altitude H reached by the missile, we can use the equation

[tex]v_y^2 = v_{0y}^2 - 2gy = (v_0\sin{45°})^2 - 2gy[/tex]

At its maximum height H, [tex]v_y = 0[/tex] so we can write

[tex]0 = (v_0\sin{45°})^2 - 2gH[/tex]

or

[tex]H = \dfrac{(v_0\sin{45°})^2}{2g}[/tex]

[tex]\:\:\:\:\:\:= \dfrac{[(9.6×10^3\:\text{m/s})\sin{45°}]^2}{2(9.8\:\text{m/s}^2)}[/tex]

[tex]\:\:\:\:\:\:= 2.4×10^6\:\text{m}[/tex]

Why metals have thermoconductivity higher than ceramic?

Answers

Answer:

Thermal Conductivity Easily Transmits Heat Among Fine Ceramics

The_____ scale is called an absolute temperature scale, and its zero point is called absolute zero.

Kelvin

Fahrenheit

Celsius

Answers

The Celcius Scale is called an absolute Temperature scale,and it's zero point called absolute zero

_______________

What is a list of all the states of matter?

Answers

Answer:

3

Explanation:

state of matter are solid

liquid and

gases

Answer:

3

Explanation:

state of a matter are solid liquid and gas

A 2 kg ball is rolling down a hill at a constant speed of 4 m/s. How much kinetic energy does the ball have?

Answers

You do 0.5 x 2kg x 4 squared so

0.5x2x16

So the answer is 16

A 0,9 -kg object attached to the end of a string swings in a vertical circle (radius = 75 cm). At the top of the circle the speed of the object is 6,5 m/s. What is the magnitude of the tension in the string at this position?

Answers

0.6 cm is the answer add it up and find the m/s hope this helps

Jack sits in the chair of a Ferris wheel that is rotating at a constant 0.150 rev/srev/s . As Jack passes through the highest point of his circular part, the upward force that the chair exerts on him is equal to one-fourth of his weight.


What is the radius of the circle in which Jack travels? Treat him as a point mass.​

Answers

Answer:

Explanation:

At the top of the arc, 3/4 of the acceleration of gravity is use to supply the necessary centripetal acceleration.

0.75g = ω²R

R = 0.75g/ω²

R = 0.75(9.81) / (0.15 rev/s)(2π rad/rev)²

R = 8.283006...

R = 8.28 m

PLEASE HELP!
A 9kg particle is initially at rest at x=0. It is subject to a single force Fx (N) which varies with x (m) as shown in the
diagram
F
2
1
0
ББ by
x
- 1
1
-2
The kinetic energy of the particle when it is at x = 3 m is:

Answers

Hi there!

With a Force/Displacement curve, we must take the integral (area underneath the curve) to calculate the work done.

We know that:

W = ΔKE

Calculate the work by finding the area underneath the force curve from

x = 0 to 3 m:

We can use a trapezoid:

A = 1/2(3 + 2)(3) = 7.5 J

This is the amount of work done, and since the object starts from rest:

7.5J = KEf - KEi (0 J)

7.5J = KEf = 7.5 J

what is photosynthesis​

Answers

Required Answer :-

: [tex] \implies[/tex] The Photosynthesis is the process of capturing light energy and transforming it into chemical energy. Green plants and several other organisms use light energy and convert carbon dioxide and water into glucose. In this process, oxygen is produced as a by-product

We also who how it's process occur

In plants and blue-green algae, the photosynthesis process takes place in chloroplasts. The chloroplast is present in all green parts of a plant – the leaves, green stems, sepals, and even in the flowers, in the form of green colour plastids. The chloroplast is found only in plant cells and is essential for photosynthesis reaction.

Photosynthesis Equation

Carbon dioxide and water are the two major factors involved in the photosynthesis reaction. It’s an endothermic reaction, and the products resulting from it are oxygen and glucose. The formula is:

6CO2 + 6H2O = C6H12O6 + 6O2

However, some bacteria don’t produce oxygen as a by-product of photosynthesis. They are called anoxygenic photosynthetic bacteria, and those who do it are called oxygenic photosynthetic bacteria.

Importance of Photosynthesis

The photosynthesis process is very important for the survival of living beings, and to continue the food chain. It also produces oxygen, which is required for breathing.

Photosynthetic Pigments

Four types of photosynthetic pigments are present in the leaves of the plants. They are:

Chlorophyll a

chlorophyll b

xanthophylls

Carotenoids

The Factors Affecting Photosynthesis

Various factors influence/affect the photosynthesis process. These are:

Light Intensity: More the light, the more will be the rate of photosynthesis. Similarly, low light will lead to a low rate of photosynthesis.

The Concentration of CO2: A higher CO2 concentration rate in a plant also accelerates the photosynthesis process. The required amount of CO2 is 300-400 PPM.

Temperature: If the temperature is between the range of 25 to 35 degrees Celsius, the photosynthesis takes place effectively.

Water: An essential amount of water is required for stomatal opening, and it’s a key factor in the process of photosynthesis.

Pollution: The increasing rate of polluting particles in the atmosphere block the pores of somatic cells, and the intake of carbon dioxide becomes difficult.

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Hope it's helps !!

The center of mass of a 1600 kg car is midway between the wheels and 0.7 m above the ground. The wheels are 2.6 m apart. (a) What is the minimum acceleration A of the car so that the front wheels just begin to lift off the ground

Answers

Answer:

Explanation:

I guess we are ASSUMING that this is a rear wheel drive car as a front wheel drive car will never get the front wheel normal force to zero

If we consider it as a statics problem and choose our moment center carefully...say 0.7 m above the rear wheel to ground contact point.

Call the traction force at the rear wheels F

The normal force on the front wheels will be zero, so no moment generated by the front wheels.

Summing moments about our chosen point to zero

1600(9.8)[2.6 / 2] - F[0.7] = 0

F = 291,200

this force will create an acceleration of

a = F/m

a = 291200/1600

a = 182 m/s²

which is about 18.6 times gravity acceleration

A car with an initial position of 10.0 m
and an initial velocity of 16.0 m/s accelerates at an average rate of 0.50 m/s2 for 4.0 s. What is the car’s position after 4.0 s?

Answers

Answer:

78

Explanation:

x=xi+vi(t)+1/2a(t)^2

x=10+16(4)+1/2(0.50)(4)^2

x=74+4

x=78 m

A tennis player strikes the tennis ball with an initial velocity of 44.7 m/s horizontally. The ball is initially 1.28 m above the ground and 12.9 m from the 0.914 m tall net. Does the tennis ball make it over the net?

Answers

Hi there!

We can begin by finding the total time taken for the ball to reach the net using the equation:

dₓ = vₓt

12.9 = 44.7t

12.9/44.7 = t = 0.289 s

Now, we can use the following equation to solve for displacement in the Y direction:

d = y₀ + vit + 1/2at²

There is no initial vertical velocity, so:

d = y₀ + 1/2at²

Plug in known values:

d = 1.28 + 1/2(-9.8)(0.289²)

d = 0.87m

Thus, since 0.87 m < 0.914 m, the tennis ball does NOT make it over the net.

If the penny is thrown horizontally at 25 m/s from the 170 meter building, how long will it take for the penny to hit the ground?

Answers

9514 1404 393

Answer:

  about 5.89 seconds

Explanation:

The penny will hit the ground at the same time it would if it were simply dropped. The equation for the vertical motion is ...

  h(t) = -4.9t^2 +170 . . . . . where 170 is the initial height in meters

h(t) = 0 when ...

  4.9t^2 = 170

  t = √(170/4.9) ≈ 5.89

The penny will hit the ground in about 5.89 seconds.

Which is the most famous book of the philosopher Alexis karpouzos? I think it is the ''Cosmology, philosophy and physics''.

Answers

Answer: Yes, the " Cosmology, philosophy and physics" is the most famous book of the philosopher, Alexis karpouzos. But and the other books are important. For example, the " The self-criticism of science", the "Universal conscilusness" and the "Non-duality".

Explanation:

Suppose you lift a 17 kg k g box by a height of 1.0 m m . How much work do you do in lifting the box

Answers

Answer:

17 J

Explanation:

work done= force X distance moved

What is the direction of the torque produced on the crankset by the 2-kg mass attached to the pedal bar

Answers

A Torque is a twisting force, or turning moment, it is a vector quantity with both magnitude and direction e.g Turning the handle of a cork-screw clockwise and then counterclockwise will advance the screw first inward and then outward By convention, counterclockwise torques are positive and clockwise torques are negative.

The direction is perpendicular to both the radius from the axis and to the force. It is conventional to choose it in the right hand rule direction along the axis of rotation.

Counterclockwise is the positive rotation direction and clockwise is the negative direction.

Learn more at:

https://brainly.com/question/18253139

please paraphrase this paragraph

As a conclusion we first learned what is Discrete Fourier Transform and
why is it very important in signal processing science as it helps us to convert the discrete signal from time domain into frequency domain and the inverse DFT does the opposite converting the signal from frequency domain back into time domain. We have also learned the difference between DFT and the FFT algorithm where the FFT is an efficient
algorithm created to simplify the DFT process as it is faster and more accurate. We also learned how to perform and implement this algorithm using Matlab,

Answers

Answer:

The importance of signal processing science as has been made clear. Since we now know that it help to convert discrete signal from time domain to frequency domain. Moreover, we are now aware of the difference in DF5 and FFT algorithms as well as the implementation in Matlab.