a 4 kg block of iron weighs about

a.) 4 N
b.) 40 N
c.) 0.4 N
d.) more than 400 N

Answers

Answer 1

Answer:

40 N

Explanation:

[tex]w = mg \\ w = 4 \times 9.81 \\ w = 39.24 = 40 \: [/tex]


Related Questions

Two blocks A and B with mA = 2.9 kg and mB = 0.87 kg are connected by a string of negligible mass. They rest on a frictionless horizontal surface. You pull on block A with a horizontal force of 6 N. Determine the tension in the string connecting the two blocks.

Answers

Answer:

Tension = 1.38 N

Explanation:

Given that:

Mass of block A [tex]m_A[/tex] = 2.9 kg

mass of block B [tex]m_B[/tex] = 0.87 kg

Force F = 6 N

Assume a = acceleration of the blocks.

Then:

[tex]m_A[/tex] (a) + [tex]m_B[/tex] (a) = 6

2.9a + 0.87a = 6

3.77a = 6

a = 6/3.77

a = 1.59 m/s²

Suppose T to be the tension in the string.

If we take a look at the forces acting on the first block, then:

F - T = [tex]m_A[/tex] (a)

T = F - [tex]m_A[/tex] (a)

T = 6 - 2.9(1.59)

T = 6 - 4.62

T = 1.38 N

A ball is spun around in circular motion such that its frequency is 10 Hz.
a. What is the period of its rotation?
b. How much time will be required to complete 100 rotations?

Answers

Answer:

a = 0.1 s b. 10 s

Explanation:

Given that,

The frequency in circular motion, f = 10 Hz

(a) Let T is the period of itsrotation. We know that,

T = 1/f

So,

T = 1/10

= 0.1 s

(b) Frequency is number of rotations per unit time. So,

[tex]t=\dfrac{n}{f}\\\\t=\dfrac{100}{10}\\\\t=10\ s[/tex]

Hence, this is the required solution.

Which element is the biggest contributor to Climate Change?

Answers

Answer:

carbon dioxide (CO2)

Explanation:

the burning or combustion of these fossil fuels creates gases that are released into the atmosphere. Of these gases, carbon dioxide (CO2) is the most common and is the gas most responsible for exacerbating the green- house effect that is changing global climate patterns.

A spherical light bulb dissipates 100W and is of 5cm diameter. Assume the emissivity is 0.8 and the irradiation is negligible. What is the surface temperature of this spherical light bulb

Answers

Answer:

[tex]T=728.9K[/tex]

Explanation:

Power [tex]P=100W[/tex]

Diameter [tex]d=5[/tex]

Radius [tex]r=2.5cm=>2.5*10^{-2}m[/tex]

Emissivity [tex]e=0.8[/tex]

Generally the equation for Area of Spherical bulb is mathematically given by

[tex]A=4\pi r^2[/tex]

[tex]A=4\pi (2.5*10^{-2}m)^2[/tex]

[tex]A=7.85*10^{-3}m^2[/tex]

Generally the equation for Emissive Power bulb is mathematically given by

[tex]E=e\mu AT^4[/tex]

Where

[tex]\mu=Boltzmann constants\\\\\mu=5.67*10^{-8}[/tex]

Therefore

[tex]T^4=\frac{E}{e\mu A}[/tex]

[tex]T^4=\frac{100}{0.8*5.67*10^{-8}*7.85*10^{-3}m^2}[/tex]

[tex]T=^4\sqrt{2.80*10^{11}}[/tex]

[tex]T=728.9K[/tex]

write the full form of MBBS pliz now​

Answers

Answer:

The full form of MBBS is Bachelor of Medicine, Bachelor of Surgery

pls mark me brainliest :))

The full form of MBBS in India is 'Bachelor of Medicine, Bachelor of Surgery'. However, MBBS is an abbreviation of Medicinae Baccalaureus Baccalaureus Chirurgiae, which is the term used for this course in Latin.

A model plane has a mass of 0.75 kg and is flying 12 m above the ground
with a speed of 18 m/s. What is the total mechanical energy of the plane?
The acceleration due to gravity is 9.8 m/s2.

Answers

Answer:

Option C. 210 J.

Explanation:

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

Mass (m) = 0.75 Kg

Height (h) = 12 m

Velocity (v) = 18 m/s

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

Total Mechanical energy (ME) =?

Next, we shall determine the potential energy of the plane. This can be obtained as follow:

Mass (m) = 0.75 Kg

Height (h) = 12 m

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

Potential energy (PE) =?

PE = mgh

PE = 0.75 × 9.8 × 12

PE = 88.2 J

Next, we shall determine the kinetic energy of the plane. This can be obtained as follow:

Mass (m) = 0.75 Kg

Velocity (v) = 18 m/s

Kinetic energy (KE) =?

KE = ½mv²

KE = ½ × 0.75 × 18²

KE = ½ × 0.75 × 324

KE = 121.5 J

Finally, we shall determine the total mechanical energy of the plane. This can be obtained as follow:

Potential energy (PE) = 88.2 J

Kinetic energy (KE) = 121.5 J

Total Mechanical energy (ME) =?

ME = PE + KE

ME = 88.2 + 121.5

ME = 209.7 J

ME ≈ 210 J

Therefore, the total mechanical energy of the plane is 210 J.

An open 1-m-diameter tank contains water at a depth of 0.5 m when at rest. As the tank is rotated about its vertical axis the center of the fluid surface is depressed. At what angular velocity will the bottom of the tank first be exposed

Answers

Answer:

Angular velocity (w) = 8.86 rad/s

Explanation:

Angular velocity (w) = [tex]\sqrt{} 4ghi/R^{2}[/tex]

g= 9.81 m/s

R= 0.5

hi (initial depth) = 0.5m

Hence= [tex]\sqrt4* 9.81* 0.5/0.5^{2}[/tex]  = 8.86 rad/s

3. How can a generator that otherwise produces AC
current be modified to produce DC current?

Answers

The change requires a commutator. ... The brushes attached to each half of the commutator are arranged so that at the moment the direction of the current in the coil reverses, they slip from one half of the commutator to the other.

A 500-nm wavelength light in vacuum illuminates a soap film with an index of refraction of 1.33. Air (n=1.00) is on both sides of the film. If the light strikes the film nearly perpindicularly, what is the smallest film thickness such that the film appears bright?
ANS --> 94.0

Please show your work as to how to end up with this answer.

Answers

Answer:

Wavelength of light in film (let y = lambda)

y = 500 nm / (4/3) = 375 nm    

There will be a phase change at the air/film interface (not the other side)

S = 4 t       thickness of film = S/4 where S equals 1 wavelength

This is because of the phase change at one surface

375 nm = 4 * t

t = 93.8 nm

A 0.200 m wire is moved parallel to a 0.500 T
magnetic field at a speed of 1.50 m/s. What emf is
induced across the ends of the wire?

Answers

Answer:

The required emf moved across the wire is zero

Explanation:

For a moving charge particle, the magnetic force can be determined by using the formula;

[tex]\varepsilon = Bvlsin \theta[/tex]

since the wire moves in parallel, the angle [tex]\theta[/tex] between magnetic field and velocity = 0°

B = 0.500 T

v = 1.50 m/s

l = 0.200 m

[tex]\varepsilon = (0.500 \ T )(1.50 \ m/s) \times (0.200 \ m)\times sin (0)[/tex]

[tex]\varepsilon = 0.15\times sin (0)[/tex]

[tex]\varepsilon = 0[/tex]

potential Energy is associated with position
True or false​

Answers

Answer:

yes.

Explanation:

potential Energy is associated with position

Answer:

true

Explanation:

the energy possessed by a body by virtue of its position or configuration is called potential energy.Everything at a height from the earth surface posseses potential energy.

What is the thinnest soap film (excluding the case of zero thickness) that appears black when illuminated with light with a wavelength of 555 nmnm

Answers

Answer:

The minimum thickness of soap film is [tex]2.086\times 10^{-7} m[/tex].

Explanation:

wavelength = 555 nm

refractive index, n = 1.33

For the destructive interference,

the thickness is given by

[tex]t =\frac{m \lambda }{2 n}[/tex]

Here, m is the order, n is the refractive index and [tex]\lambda[/tex] is the wavelength.

For minimum thickness, m = 1

So the thickness is  

[tex]t =\frac{1 \times 555\times 10^{-9} }{2 \times 1.33}\\\\t = 2.086\times 10^{-7} m[/tex]

A stalled car is being pushed up a hill at constant velocity by three people. The net force on the car is Group of answer choices Zero down the hill and greater than the weight of the car. down the hill and equal to the weight of the car up the hill and equal to the weight of the car. up the hill and greater than the weight of the car.

Answers

Answer:

Zero

Explanation:

Net force can be defined as the vector sum of all the forces acting on a body or an object i.e the sum of all forces acting simultaneously on a body or an object.

Mathematically, net force is given by the formula;

[tex] Fnet = Fapp + Fg[/tex]

Where;

Fnet is the net force.

Fapp is the applied force.

Fg is the force due to gravitation.

In this scenario, a stalled car is being pushed up a hill at constant velocity by three people. Thus, the net force on the car is zero because all the forces acting on any physical object is equal to zero and represents a constant velocity; by balancing or cancelling each other out.

According to Sir Isaac Newton's First Law of Motion which is known as Law of Inertia, it states that an object or a physical body in motion will continue in its state of motion at continuous velocity (the same speed and direction) or, if at rest, will remain at rest unless acted upon by an external force.

A proton accelerates from rest in a uniform electric field of 595 N/C. At one later moment, its speed is 1.15 Mm/s (nonrelativistic because v is much less than the speed of light). (a) Find the acceleration of the proton. (b) Over what time interval does the proton reach this speed? (c) How far does it move in this time interval? (d) What is its kinetic energy at the end of this interval?

Answers

At one later moment, its speed is 1. 20Mm/s (non relativistic because v is much less than the speed of light).

Select the correct answer.
A car traveling south is 200 kilometers from its starting point after 2 hours. What is the average velocity of the car?
O A 100 khmeters/hour south
OB. 200 kilometers/hour
Ос.
200 kilometers/hour north
OD.
100 kilometers/hour

Answers

Answer:

D

Explanation:

The velocity of the car would be 100 kilometer per hour.

D that should be correct boo

An aircraft is in level flight at 225 km/hr through air at standard conditions. The lift coefficient at this speed is 0.45 and the drag coefficient is 0.065. The mass of the aircraft is 900 kg. Calculate the effective lift area for the aircraft and the required engine thrust and power to maintain level flight.

Answers

Answer:

- the effective lift area for the aircraft is 8.30 m²

- the required engine thrust is 1275 N

- required power is 79.7 kW

Explanation:

Given the data in the question;

Speed V = 225 km/hr = 62.5 m/s

The lift coefficient CL = 0.45

drag coefficient CD = 0.065

mass = 900 kg

g = 9.81 m/s²

a)  the effective lift area for the aircraft

we know that for a steady level flight, weight = lift and thrust = drag

Using the equation for the lift force

F[tex]_L[/tex] = C[tex]_L[/tex][tex]\frac{1}{2}[/tex]ρV²A = W

we substitute

0.45 × [tex]\frac{1}{2}[/tex] × 1.21 × ( 62.5 )² × A = ( 900 × 9.81 )

1081.05 × A = 8829

A = 8829 / 1081.05

A = 8.30 m²

Therefore, the effective lift area for the aircraft is 8.30 m²

b) the required engine thrust and power to maintain level flight.

we use the expression for drag force

F[tex]_D[/tex] = T = C[tex]_D[/tex][tex]\frac{1}{2}[/tex]ρV²A

we substitute

= 0.065 × [tex]\frac{1}{2}[/tex] × 1.21 × ( 62.5 )² × 8.30

T = 1275 N

Since drag and thrust force are the same,

Therefore, the required engine thrust is 1275 N

Power required;

P = TV

p = 1275 × 62.5

p = 79687.5 W

p = ( 79687.5 / 1000 )kW

p = 79.7 kW

Therefore, required power is 79.7 kW

option are
cerebrum, cortex, cerebellum, brain stem, medulla, pons, midbrain , thalamus, hypothalamus, reticular formation

1.________regulates and maintains brain's awareness level.

2. _______controls the activity of the pituitary gland.

3._______relays impulses from one part of the brain to another.

4._______regulates body temperature, hunger, and other internal body conditions.

5______connects nerve impulses from body to cortex.

Answers

Answer:

1. Reticular formation.

2. Hypothalamus.

3. Thalamus.

4. Hypothalamus.

5. Thalamus.

Explanation:

The human brain consists of various sections and these includes;

I. Anterior Cingulate Cortex (ACC) which resembles a bow or collar surrounding the frontal part of the corpus callosum. This is the frontal part of the cingulate cortex which helps to make complex cognitive functions such as impulse control, decision-making, emotions and empathy.

II. Ventral prefrontal cortex in humans are interconnected with the brain and are responsible for the processing of risk, empathy, fear and social decision-making

III. The Cerebral Cortex: this part of the brain primarily comprises of grey matter, foldable sheets of neurons and forms its outermost layer. Therefore, cerebral cortex is known as the outermost layer of the brain (cerebrum) and thus, makes up half of its weight. It is about 2.5 millimeters in thickness and as such it's able to fold.

1. Reticular formation: regulates and maintains brain's awareness level.

2. Hypothalamus: controls the activity of the pituitary gland.

3. Thalamus: relays impulses from one part of the brain to another.

4. Hypothalamus: regulates body temperature, hunger, and other internal body conditions.

5. Thalamus: connects nerve impulses from body to cortex.

4. A 268 kg boulder rolls down a hill. If it had 50,000 J of energy to start with, how high was the hill? (Can anyone explain or give the equation for it? Thank you!)​

Answers

Answer:

h = 18.65 m

Explanation:

Given that,

The mass of a boulder, m = 268 kg

The potential energy at the hill, E = 50,000 J

We need to find the height of the hill.

We know that, the potential energy of an object is given by :

E = mgh

Where

h is the height of the hill

So,

[tex]h=\dfrac{E}{mg}\\\\h=\dfrac{50000}{268\times 10}\\\\h=18.65\ m[/tex]

So, the height of the hill is 18.65 m.

Mass=268kg=mP.E=50000Jacceleration due to gravity=g=10m/s^2Height be h

[tex]\\ \sf\longmapsto PE=mgh[/tex]

[tex]\\ \sf\longmapsto 50000=268(10)h[/tex]

[tex]\\ \sf\longmapsto 50000=2680h[/tex]

[tex]\\ \sf\longmapsto h=\dfrac{50000}{2680}[/tex]

[tex]\\ \sf\longmapsto h=18.65m[/tex]

Calculate the force exerted on a thresher shark's eye by the hydrostatic pressure in ocean water at a depth of 380 m. (Assume the water's mass density at this depth is 1000 kg/m3k.)

Answers

Answer:

Explanation:

Hydrostatic pressure due to a water column of height  h can be given by the following expression.

P = hρg

where ρ is density of water and g is acceleration due to gravity .

Substituting the values.

P = 380 x 1000 x 9.8

= 3.72 x 10⁶ Pa.

Answer:

[tex]F=\dfrac{3.72\times 10^6\ Pa}{A}\ N[/tex]

Explanation:

Given that,

The density of water, d = 1000 kg/m³

Depth, h = 380 m

We need to find the force exerted on a thresher shark's eye by the hydrostatic pressure in ocean water. The force exerted by the hydrostatic pressure is given by :

[tex]P=\rho gh[/tex]

Put all the values,

[tex]P=1000\times 9.8\times 380\\\\P=3.72\times 10^6\ Pa[/tex]

Force exerted,

F = P/A

So,

[tex]F=\dfrac{3.72\times 10^6\ Pa}{A}\ N[/tex]

Where

A is the area of crosss section

Hence, this is the required solution.

The conversion of thermal energy into mechanical energy requires
a thermometer.
D. Beat engine
C vaporizer.
d thermostat.

Answers

Temperature difference is required, so i’m guessing - a. thermometer - would be required to check that temperature.

Long Shore Drift is the ...
A. landforms along the shoreline of an ocean or sea
B. submerged or partly exposed ridge of sand along an ocean front
C. accumulation of sand grains along a beach front
D. movement of material along a coast by waves that approach at an angle to the shore.​

Answers

Answer: D. movement of material along a coast by waves that approach at an angle to the shore.​

Explanation:

Longshore drift is also referred to as the littoral druft and it means the sediment that is moved by the longshore current.

Longshore drift is the movement of material along a coast by waves which approach at an angle to the shore but then recede down the beach.

Therefore, the correct option is D.

write the chemical equation of rust ​

Answers

ANSWER

4Fe+ 3O2 → 2Fe2O.

EXPLANATION

iron (Fe) combines with oxygen (O2) to form rust, or iron oxide (Fe2O3). The equation for this reaction is: 4Fe+ 3O2 → 2Fe2O.

The answer is O2+Fe+H20—>Fe2O3H20

Is an object on the surface of Earth sitting still relative to outer space?

Answers

Answer:

The object is not still as it observe from the outer space.

Explanation:

Our earth is not stationary.

It rotates about its own axis with the period of 24 hours and it revolves around the sun with the period of 1 year.

An object is said to be at rest if the position of the object with respect to time changes.

An object is said to be in motion when the position of the object changes with respect to time.

Both the terms rest and motion are relative to each other.  

If an observer observe an object on the earth from the outer space, he observe that the object s not still it is also moving as the earth is moving.

So, the object is not still as it observe from the outer space.

Select the correct answer.
A force of 100 newtons is applied to a box at an angle
acceleration of the box?
36° with the horizontal. If the mass of the box is 25 kilograms, what is the horizontal
OA
1.52 meters/second2
3.24 meters/second
C.
5.48 meters/second
Ο Ο Ο Ο
6.87 meters/seconda
7.15 meters/second

Answers

Answer:

3

Explanation:

first you find the original component of the force be a cause in 36 degrees then with ka sin 36 find the average interforce by multiplying it with hundred Newton then divide the original force by the mass 25 Kg is equals tto ma

Answer:

See image

Explanation:

Plato

Thiết kế mạch điện tử sử dụng chân ngõ ra (I/O) của arduino UNO để lái relay 12VDC/500mA sao cho chân Arduino xuất ra tín hiệu 5V thì relay đóng, ngược lại chân I/O arduino xuất tín hiệu 0V thì relay hở. Mạch lái dùng BJT

Answers

Answer:

Mình cũng không biết làm bạn ơi =)))

Explanation:

Describe how the human ear hears sound.

Answers

Answer:

sound waves enter the outer ear and travel through a narrow passageway called the ear canal, which leads to the eardrum. The eardrum vibrates from the incoming sound waves and sends these vibrations to three tiny bones in the middle ear.

Explanation:

What kind of force are you using when you squish a marshmallow?

Answers

The answer is compression because when you are squishing a marshmello you are compressing it.

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