A block is pushed so that it moves up a ramp at constant speed. Identify from choices (a)-(e) below the appropriate description for the work done by the specified force while the block moves from point A to point B. (a) is zero. (b) is less than zero. (c) is greater than zero. (d) could be positive or negative depending on the choice of coordinate systems. (e) cannot be determined.

Answer:

weight

Explanation:

weight is the pull of gravity so its a force !!

Frequency = (speed) / (wavelength)

Frequency = (3 x 10⁸ m/s) / (124 x 10⁻⁹ m)

Frequency = 2.42 x 10¹⁵ Hz

Answer:

the power that can be generated by the river is 117.6 MW

Explanation:

Given that;

Volume flow rate of river v = 240 m³/s

Height above the lake surface a h = 50 m

Amount of power can be generated from this river water after the dam is filled = ?

Now the collected water in the dam contains potential energy which is used for the power generation,

hence, total mechanical energy is due to potential energy alone.

[tex]E_{mech}[/tex] = m(gh)

first we determine the mass flow rate of the fluid m

m = p×v

where p is density ( 1000 kg/m³

so we substitute

m = 1000kg/m³ × 240 m³/s

m = 240000 kg/s

so we plug in our values into ( [tex]E_{mech}[/tex] = m(gh) kJ/kg )

[tex]E_{mech}[/tex] = 240000 × 9.8 × 50

[tex]E_{mech}[/tex] = 117600000 W

[tex]E_{mech}[/tex] = 117.6 MW

Therefore, the power that can be generated by the river is 117.6 MW

Answer:

In my physics class, something that helps connect better with kids is keeping connected with them always make sure to ask if they understand what you're teaching if they are following because sometimes most kids are to afraid to admit that they are lost, another way to connect with kids is maybe posting surveys to be able to check in with each student especially during this hard times :)

Explanation:

1. start with fun activities.

2. Encourage single-tasking.

3. Designate a learning playing field.

Answer:

One sphere obtains a positive charge, while the other obtains a negative charge.

Explanation:

When the negatively-charged rod is brought close to the two neutral spheres in contact with each other, the electrons in both spheres are repelled away from the rod and thus those electrons move into the second sphere farther away from the rod.

The first sphere is now short of electrons.

When the spheres are separated, the first sphere which is short of electrons now carries a net positive charge, while the other sphere which has excess electrons now carries a net negative charge.

Answer:

D

Explanation:

because it doesn't agree with the law of definite proportion

and energy can niether be created nor destroyed but can be transformed from one form to another

The false statement will be, The total amount of energy changes upon an energy transformation.

The conservation of energy according to the first law of thermodynamics is that energy neither be created nor be destroyed, but can be transformed from one form to another form.

Now we can take many examples like if we are running a bicycle our efforts are converted to the rotation of the wheel and the rotation energy is converted to the linear energy of our motion.

But the necessary point is that from the second law of thermodynamics it states that the energy can not be completely converted to the other form but some part of it is losses in the environment.

Thus the false statement will be, The total amount of energy changes upon an energy transformation.

To know more about laws of conservation of energy, follow

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Answer: reduced by 1/4

Explanation:

The force will be reduced by 1/4. Try plugging in 2r, then squaring it. You will get 4r^2, which is essentially dividing the force by 4

Answer: 3. To give the object a negative charge we must give it more electrons, and this will increase its mass.

Explanation:

Suppose we have an object and we negatively charge it.

Then we are "adding" N electrons to the object.

Remember that the mass of an electron is:

m = 9.11*10^(-31) kg

Then if we add N electrons to an object of mass M, the new mass of the object will be:

Mass = M + N*9.11*10^(-31) kg

So we will have an (almost negligible) increase of the mass of the object.

(Something similar can happen if the object is positively charged, where we remove electrons, then the mass of the object decreases)

Then the correct option is:

3. To give the object a negative charge we must give it more electrons, and this will increase its mass.

Answer:

Explanation:

When two north magnetic poles are  placed close to each other , they will repel each other . If distance between them is increased due to mutual repulsion from x to 12 x , work is done by the magnetic field . This results in decrease of magnetic field energy .

Hence , when the distance between the poles becomes 12x from x , the magnitude of the field energy between them decreases .

Explanation:

The vertical component the velocity of the projectile is 15 m/s x sin 30 = 7.5 m/s.

The body is accelarating downwards at 10 m/s^2.

This means that every second its upward velocity reduces by 10 m/s.

So if the body is travelling upwards at 7.5 m/s then how long does it take for the velocity to become 0?

(7.5 m/s) / (10 m/s^2) = 0.75 s

Answer:

True :p

Explanation:

Carbohydrates are foods that get converted into glucose.

Answer:

power...............m....

Answer:

The dimension of power is energy divided by time. In the International System of Units (SI), the unit of power is the watt (W), which is equal to one joule per second.

SI unit: watt (W)

In SI base units: kg⋅m2⋅s−3

Explanation:

Answer:

a) frequency = 0.1724 Hz

b) Period = 5.8 sec

c) speed = 7.04 m/s

d) acceleration = 7.62 m/s²

Explanation:

Given that;

radius = 6.5m

time period = 5.8 sec every circle

a)  the frequency

frequency is the number of rotation in unit time

frequency = 1 / time period = 1/5.8

frequency = 0.1724 Hz

b)  the period

period is time taken in one rotation

period = total time / rotation = 5.8 / 1

Period = 5.8 sec

c)  the speed

speed = distance/time = circumference/time period = 2πr / t = (2π×6.5) / 5.8

speed = 7.04 m/s

d) acceleration

To find the acceleration we take the linear velocity squared divided by the radius of the circle.

so

acceleration = v² / r = (7.04)² / 6.5 = 49.5616 / 6.5

acceleration = 7.62 m/s²

Explanation:

O + 6V = 9V, so O = 3V

P = 9V as it is parallel to the 9V power supply.

For answering this question,let us assume that a person is pushing against the walls,so now:

Which object exerts the action force?

Which object exerts the reaction force?

In what direction does the action force push?

In what direction does the reaction force push?

The answer varies from different scenarios.

Answer:

diver, diving board, down, and up.

Explanation:

Answer:

astronomi

Explanation:

sciemce ya ya

Answer:Purpose of Cloning

A forensic image of a hard drive captures everything on the hard drive, from the physical beginning to the physical end. ... Hard drives are susceptible to failure. Having two clones gives an investigator one to examine and one to fall back on.Therapeutic cloning involves creating a cloned embryo for the sole purpose of producing embryonic stem cells with the same DNA as the donor cell. These stem cells can be used in experiments aimed at understanding disease and developing new treatments for disease.

Explanation:

hope this helps have a nice night lo❤️❤️❤️l

Cloning

Cloning is defined as a technique used by scientists to make exact genetic copies of living things. Genes, cells, tissues, and even whole animals can all be cloned.

Everything on the hard drive is captured by the forensic image. Hard drives can be a failure. If possible, the original drive should be preserved in a safe place and only brought out to reimage if needed. Ideally, all examinations are done on a clone as opposed to the original.

One of the cloning types is Therapeutic cloning which involves creating a cloned embryo for the sole purpose of producing embryonic stem cells with the same DNA as the donor cell. These stem cells can be used in experiments aimed at understanding disease and developing new treatments for disease.

To know more about cloning, follow the link given below.

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Answer:

the speed and aceleration of the ping pong ball is greater than that of the bowling ball.

Explanation:

We can analyze this exercise from several points of view, if we use Newton's second law

Bowling ball

           F = M a₁

pingpongg ball

           F = m a₂

as the forces the same

          M a₁ = m a₂

          a₂ = [tex]\frac{M}{m}[/tex] a₁

Since the mass of the bowling ball is much greater than the ping pong ball,

          a₂ »a₁

so the acceleration of the ping pong ball is much greater than the acceleration of the bowling ball.

If we use the relationship of momentum and momentum, assuming that the time for the two cases is the same and that both start from rest

Bowling ball

           I = F t = Δp

           I = M (v₁ - v₀)

Ping pong ball

           I = F t = Δp

           I = m (v₂ -v₀)

the impulse itself

          M v₁ = m v₂

          v₂ = [tex]\frac{M }{ m}[/tex] v₁

so we conclude that the speed of the ping pong ball is much greater than the speed of the bowling ball.

In conclusion the speed and aceleration of the ping pong ball is greater than that of the bowling ball.

Answer:

The starting velocity.

Explanation:

We must understand that this equation comes from the following equation of kinematics.

[tex]v_{f}=v_{o}+a*t[/tex]

where:

Vf = final velocity = 33 [m/s]

Vo = starting velocity [m/s]

a = acceleration = 3 [m/s²]

t = time = 30 [s]

So, these values can be assembly in the following way:

[tex]v_{f}=v_{o}+a*t\\a*t=v_{f}-v_{o}\\3=\frac{33-v_{o}}{30}[/tex]

Answer:

Explanation:

Maximum height reached = 90.6 m . Range = 48.5 m

. Let u be the initial velocity at angle α .

Horizontal range is covered by horizontal component of u .

Vertical height is achieved by vertical component

v² = u² sin² α - 2gh , t is time taken to attain maximum height .

0 = u² sin² α - 2 x 90.6 x 9.8  

u² sin² α = 2 x 887.88  -------( 1 )

Range R = u² sin2α / g

48.5 = 2 u² sinα . cos α / 9.8

u² sinα . cos α = 237.65 -----------------------------  ( 2 )

( 1 ) / ( 2 )

Tan α = 2 x 887.88 / 237.65 = 7.47

α = 82⁰

u² sin² α = 2 x 887.88

u² sin² 82 = 2 x 887.88

u² = 1812

u = 42.56  m /s

Solution :

Length of the plastic rod , L = 1.6 m

Total charge on the plastic rod , Q = [tex]$-9 \times 10^{-8}$[/tex] C

The rod is divided into 8 pieces.

a). The length of the 8 pieces is , [tex]$l=\frac{L}{8}$[/tex]

                                                         [tex]$=\frac{1.6}{8}$[/tex]

                                                         = 0.2 m

b). Location of the center of the piece number 5 is given as : 0 m, -0.09375 m, 0 m.

c). The charge q on the piece number 5 is given as

[tex]$q=\frac{Q}{L}\times l$[/tex]

[tex]$q=\frac{-9 \times 10^{-8}}{1.6}\times0.2$[/tex]

 = [tex]$-1.125 \times 10^{-8}$[/tex] C

d). WE approximate that piece 5 as a point charge and we need to find out the field at point A(0.7 m, 0, 0) only due to the charge.

We know,  the Coulombs force constant, k = [tex]$8.99 \times 10^9 \ N.m^2/C^2$[/tex]

So the X component of the electric field at the point A  is given as

[tex]$E_x = 8.99 \times 10^9 \times 1 \times 10^{-8} \ \cos \frac{187.628}{0.70625}$[/tex]

     = -126.15 N/C

The Y component of the electric field at the point A is

[tex]$E_y = 8.99 \times 10^9 \times 1 \times 10^{-8} \ \sin \frac{187.628}{0.70625}$[/tex]

    = -16.93 N/C

Now since the rod and the point A is in the x - y plane, the z component of the field at point A due to the piece 5 will be zero.

∴ [tex]$E_z=0$[/tex]

Thus, [tex]$E= <-126.15,-16.93,0>$[/tex]

Answer:

ΔV = - 3274 V

Explanation:

For this exercise we can use conservation of energy

starting point.

         Em₀ = U = q ΔV

final point

          Em_f = K = ½ m v²

energy is conserved

          Em₀ = Em_f

          q ΔV = ½ m v²

          ΔV = [tex]\frac{m \ v^2 }{q}[/tex]

let's calculate

          ΔV = [tex]\frac{4.4 \ 10^{-6} \ 80^2 }{ 2 \ 4.3 10^{-6} }[/tex]

          ΔV = 3274.4 1 V

since the charge q is negative, the potential at point B must be less than the potential at point A, so the answers

          ΔV = - 3274 V

Answer:

True

Explanation:

The kinetic energy of an object is the energy that it possesses due to its movement or motion.

True, the amount of kinetic energy an object has depends on its mass and its speed.

The kinetic energy of a moving object is directly proportional to the square of its velocity and directly proportional to its mass.

Answer: [tex]p_{x}=[/tex] 0.0135814 kg.m/s

              [tex]p_{y}=-0.000219[/tex] kg.m/s

Explanation: When an object with mass is in motion, we say the object has momentum (p). Momentum is dependent on mass and velocity:

p = m.v

The total momentum of Bryce's mice is calculated as

x-axis

[tex]p_{x}=\Sigma m.v_{x}[/tex]

[tex]p_{x}=[(0.0213)(0.675)+(0.0165)(-0.249)+(0.0185)(0.395)+(0.0193)(-0.207)][/tex]

[tex]p_{x}=[/tex] 0.0135814

At the x-axis, total momentum of Bryce's mice is 0.0135814 kg.m/s.

y-axis

[tex]p_{y}=\Sigma m.v_{y}[/tex]

[tex]p_{y}=[(0.0213)(-0.417)+(0.0165)(-0.809)+(0.0185)(0.953)+(0.0193)(0.227)][/tex]

[tex]p_{y}=-0.000219[/tex]

At the y-axis, total momentum of Bryce's mice is -0.000219 kg.m/s.

Answer:

A student could conclude that the cart gained momentum as it rolled down.

Explanation:

If the cart was allowed to roll down the ramp from rest, it means that the initial velocity of the cart is zero (0). Also, if the final velocity of the cart became 25 cm/s, it means that the velocity of the cart increased from 0 to 25 cm/s.

Therefore, A student could conclude that the cart gained momentum as it rolled down.

Answer:

32kg = 313.6N

82kg = 803.6N

1000kg = 9800N

524N = 53.47kg

441N = 45kg

51N = 5.20kg

for the box diagram the weight of the 15kg box is 147N

the net force will be equal to zero because the box is motionless

Fg goes downward arrow of box 147N

Fnorm goes upward arrow of box 147N

Answer:

Mary will have to wait for 63.2 seconds

Explanation:

Time required for the apple to drop from a height of 17.0 m above the ground to 1.65 m above the ground is given by the formula below:

t = √2h/g  where h is height through which the object falls, g is acceleration due to gravity

h = 17.0 - 1.65 = 15.35 m

g = 9.8 m/s²

t = √(2 * 15.35/9.8)

t = 1.77 s or approximately 1.8 s

Time taken for bill to get to the point below Mary's window is given below;

time taken = distance/velocity

distance = 130 m; velocity = 2.0 m/s

time taken by Bill = 130/2.0 = 65 s

Therefore, Mary will have to wait for (65 - 1.8) s = 63.2 seconds

Mary should have to wait for 63.2 seconds

t = √2h/g

here h is height via which the object falls,

g represent acceleration due to gravity

So,

h = 17.0 - 1.65

= 15.35 m

And,

g = 9.8 m/s²

Now

t = √(2 * 15.35/9.8)

t = 1.77 s or approximately 1.8 s

Now the time taken should be

= 130/2.0

= 65 s

So,

= (65 - 1.8) s

= 63.2 seconds

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Answer:

Ultraviolet rays from sun are very harmful from skin and can cause sunburn and skin diseases especially ultraviolet B rays. A sunscreen  lotion act as a protection barrier on the skin that restrict the direct contact of UV rays with skin and filter the harmful rays to enter the skin.

Radiotherapy is a medical therapy use to treat cancer. Radiotherapy commonly uses x-rays and gamma rays because they are high-energy particles or waves that kills or destroys the cancer cells.

Sunscreen lotion is able to filter this damaging ultraviolet radiation and prevent it from damaging the skin.

The sun reaches us from outer space brings ultraviolet rays to us. Ultraviolet rays are known to have some damaging effects on the skin. One way to protect our skin from this damaging ultraviolet rays is to use sunscreen lotion which is able to filter this damaging ultraviolet radiation and prevent it from damaging the skin.

X-rays and gamma rays are used in radiotherapy because they are light energy rays which are able to penetrate and destroy malignant cells in the body.

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