A box of mass 0.8 kg is placed on an inclined surface that makes an angle 30 above
the horizontal, Figure 1. A constant force of 18 N is applied on the box in a direction 10°
with the horizontal causing the box to accelerate up the incline.
The coefficient of
kinetic friction between the block and the plane is 0.25.

Show the free body diagrams

(a) Calculate the block's
acceleration as it moves up the incline. (6 marks)

(b) If the block slides down at a constant speed, find the value of force applied.
(4 marks)

​

induced emf value is missing..

please correct the question

Answer:

The new acceleration would be 9 m/s².

Explanation:

Acceleration of an object is 6 m/s²

Net force is equal to the product of mass and acceleration i.e.

F = ma

[tex]a=\dfrac{F}{m}\\\\\dfrac{F}{m}=6\ m/s^2[/tex]

If the net force was tripled and the mass were doubled, it means,

F' = 3F

m' = 2m

Let a' is new acceleration. So,

[tex]a'=\dfrac{F'}{m'}\\\\a'=\dfrac{(3F)}{(2m)}\\\\a'=\dfrac{3}{2}\times \dfrac{F}{m}\\\\a'=\dfrac{3}{2}\times 6\\\\a'=9\ m/s^2[/tex]

So, the new acceleration would be 9 m/s².

Answer:

the expression is False

Explanation:

From the kinematics equations we can find the speed of a body in a clean fall

        v = v₀ - g t

         v² = V₀² - 2 g y

If the body starts from rest, the initial speed is zero (vo = 0)

            v= √ (2g y)

In the first equation it gives us the relationship between speed and time.

With the second equation we can find the speed in which the distance works, this is the expression, see that speed is promotional at the height of a delicate body.

Therefore the expression is False

Answer:

The answer is 40 N for APX

Explanation:

Answer:

Explanation:

The volume of the spherical balloon is expressed as V = 4/3πr³ where r is the radius of the spherical balloon. If the spherical balloon is inflated with gas at the rate of 500 cubic centimetres per minute then dV/dt = 500cm³.

Using chain rule to express dV/dt;

dV/dt = dV/dr*dr/dt

dr/dt is the rate at which the radius of the gallon is increasing.

From the formula, dV/dr = 3(4/3πr^3-1))

dV/dr = 4πr²

dV/dt = 4πr² *dr/dt

500 =  4πr² *dr/dt

If radius r = 40;

500 = 4π(40)² *dr/dt

500 = 6400π*dr/dt

dr/dt = 500/6400π

dr/dt = 5/64π

dr/dt  = 0.245cm/min

Hence, the radius of the balloon is increasing at the rate of 0.245cm/min

Answer:

The  total energy is  [tex]T = 169.02 \ J[/tex]

Explanation:

From the question we are told that

    The  Poynting vector (energy flux ) is  [tex]k = 0.939 \ W/m^2[/tex]

    The length of the rectangle is  [tex]l = 1.5 \ m[/tex]

    The  width of the rectangle is  [tex]w = 2.0 \ m[/tex]

    The time taken is [tex]t = 1 \ minute = 60 \ s[/tex]

The total electromagnetic energy falls on the area is mathematically represented as

      [tex]T = k * A * t[/tex]

Where A  is the area of the rectangle which is mathematically represented as

           [tex]A= l * w[/tex]

 substituting values

         [tex]A= 2 * 1.5[/tex]

        [tex]A= 3 \ m^2[/tex]

substituting values

        [tex]T = 0.939 * 3 * 60[/tex]

        [tex]T = 169.02 \ J[/tex]

Answer:

Vf = 14.7 m/s

Explanation:

Vf² = Vi² + 2 * a * Δy

given:

a = 9.81 m/s²

Δy = 11m

Vi = 0 when upon release

Vf² = 0 + 2 (9.81) 11

Vf = 14.7 m/s

The velocity of the ball when it hits the ground will be 14.7 m/s.

The change of displacement with respect to time is defined as the velocity.  Velocity is a vector quantity. it is a time-based component. Velocity at any angle is resolved to get its component of x and y-direction.

given:

a(gravitational acceleration) = 9.81 m/s²

s (distance)= 11m

v is final velocity

u is the initial velocity

From Newton's second equation of motion;

[tex]\rm v^2 = u^2+2as \\\\ v^2=2 \times 9.81 \times 11 \\\\ v= 14.7 \ m/sec[/tex]

Hence, the velocity of the ball when it hits the ground will be 14.7 m/s.

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#SPJ2

Answer:effective

Explanation:

Answer:

one with only gravity acting upon it

Explanation:

Edgenuity :)

Answer:

7.91 m/s

Explanation:

Speed: This can be defined as the ratio of this to time. Speed can also be the magnitude of a velocity or speed is velocity without direction.

The S.I unit of speed is m/s.

From the question,

K.E = 1/2(mv²)................ Equation 1

Where K.E = Kinetic Energy, m = mass of the runner, v = velocity of the runner.

make  v the subject of the equation

v = √(2K.E/m).................Equation 2

Given: K.E = 1.09×10³ J, m = 34.8 kg.

Substitute into equation 2

v = √(2× 1.09×10³/34.8)

v = √(62.64)

v = 7.91 m/s.

Hence the speed of the runner = 7.91 m/s

Answer:

6.8%

Explanation:

According to Stefan-Boltzmann law, radiation is directly proportional with temperature raised to the fourth power:

P ∝ T⁴

Writing a proportion:

P₁ / P₂ = T₁⁴ / T₂⁴

1.3P / P = (T₁ / T₂)⁴

T₁ / T₂ = ∜1.3

T₁ = 1.068 T₂

The temperature increased by 6.8%.

Answer:

Q = -3280J

Explanation:

From the First Law of Thermodynamics, energy cannot be created nor destroyed but it can be converted from one form to another with the interaction of heat. Mathematically, this can be expressed as:

ΔU = Q + W        ----------(i)

Where;

ΔU = total change in internal energy of a system.

Q = heat exchanged between the system and the surrounding

W = work done by or on the system.

If heat is lost into the surrounding, then Q = -ve, else Q = +ve

If work is done on the system, then W = -ve, else W = -ve

=> From the question, Rick is the system and does a work of

W = +1090J  [since Rick does the work, W = +ve]

=>Also, the internal energy decreases by 2190J, therefore,

ΔU = -2190J   [since there is a decrease in internal energy]

Substitute the values of W and ΔU into equation (i) as follows;

-2190 = Q + 1090

=> Q = -2190 - 1090

=> Q = -3280J

Therefore, the value of Q = -3280J

Answer:

you need momentum in order to release energy. For example, if you need to push something heavy and you get a running head start, then it will be easier.

Explanation:

Answer

fringe separation l distance between maxima decreases

Explanation:

Because the wavelength of blue light is smaller than that if red light

Answer:

The moment of inertia of a slender uniform rod of length L about an axis at one end perpendicular to the rod is [tex]I = \frac{1}{3}\cdot m \cdot L^{2}[/tex].

Explanation:

Let be an uniform rod of length L whose origin is located at one one end and axis is perpendicular to the rod, such that:

[tex]\lambda = \frac{dm}{dr}[/tex]

Where:

[tex]\lambda[/tex] - Linear density, measured in kilograms per meter.

[tex]m[/tex] - Mass of the rod, measured in kilograms.

[tex]r[/tex] - Distance of a point of the rod with respect to origin.

Mass differential can translated as:

[tex]dm = \lambda \cdot dr[/tex]

The equation of the moment of inertia is represented by the integral below:

[tex]I = \int\limits^{L}_{0} {r^{2}} \, dm[/tex]

[tex]I = \lambda \int\limits^{L}_{0} {r^{2}} \, dr[/tex]

[tex]I = \lambda \cdot \left(\frac{1}{3}\cdot L^{3} \right)[/tex]

[tex]I = \frac{1}{3}\cdot m \cdot L^{2}[/tex] (as [tex]m = \lambda \cdot L[/tex])

The moment of inertia of a slender uniform rod of length L about an axis at one end perpendicular to the rod is [tex]I = \frac{1}{3}\cdot m \cdot L^{2}[/tex].

Answer:

Explanation:

According to first law of thermodynamics:

∆U= q + w

= 10kj+(-70kJ)

-60kJ

, w = + 70 kJ

(work done on the system is positive)

q = -10kJ ( heat is given out, so negative)

∆U = -10 + (+70) = +60 kJ

Thus, the internal energy of the system decreases by 60 kJ.

The work done by tensional force of the rope is 2.25 J and the work done by gravity is 36.75 J.

The given parameters;

The work done by the tension is calculated as follows;

W = Fd

W = 15 x 0.15

W = 2.25 J

The work done by gravity is calculated as;

W = (25 x 9.8) x 0.15

W = 36.75 J

Thus, the work done by tensional force of the rope is 2.25 J and the work done by gravity is 36.75 J.

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(a) The drift speed of electrons in the wire is 2.22 x 10⁻⁴ m/s.

(b) The potential difference between two points in the wire is 0.013 V.

The given parameters;

The drift speed of electrons in the wire is calculated as follows;

[tex]v_d = \frac{I}{qn A} \\\\but , \ \frac{I}{A} = \frac{E}{\rho} \\\\v_d = \frac{E}{qn \rho}[/tex]

where;

[tex]v_d = \frac{0.052}{1.602 \times 10^{-19} \times 8.5\times 10^{28} \times 1.72 \times 10^{-8}} \\\\v_d = 2.22 \times 10^{-4} \ m/s[/tex]

The potential difference between two points in the wire, separated by 25 cm;

V = Ed

where;

V = 0.052 x 0.25

V = 0.013 V

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Answer:

F = 213.75 N

Explanation:

First we need to calculate the angular acceleration of merry-go-round. For that purpose we use 1st equation of motion in angular form.

ωf = ωi + αt

where,

ωf=final angular velocity=(5.5 rev/min)(2π rad/1 rev)(1 min/60 s)=0.58 rad/s

ωi =initial angular velocity = 0 rad/s

t = time = 12 s

α = angular acceleration = ?

Therefore,

0.58 rad/s = 0 rad/s + α(12 s)

α = (0.58 rad/s)/(12 s)

α = 0.05 rad/s²

Now, we shall find the linear acceleration of the merry-go-round:

a = rα

where,

a = linear acceleration = ?

r = radius = 4.5 m

Therefore,

a = (4.5 m)(0.05 rad/s²)

a = 0.225 m/s²

Now, the force is given by Newton;s 2nd Law:

F = ma

where,

F = Force = ?

m = mass pf merry-go-round = 950 kg

Therefore,

F = (950 kg)(0.225 m/s²)

F = 213.75 N

Answer:

Explanation:

know that there is no external force on skater and the stone so the total momentum of the system will remains constant

so we will have

here we have

so the skater will move back with above speed

now the deceleration of the skater is due to friction given as

Answer:

(a) 3.553 m/s

(b) 21.46 m

Explanation:

(a) Applying the law of of momentum,

Total momentum before collision = Total momentum after collision

mu+m'u'  = mv+m'v'.................. Equation 1

Where m and m' are the mass of skater and stone respectively,  u and u' are the initial velocity of skater and stone respectively, v and v' are the final velocity of the skater and the stone respectively.

Note, u = 0 m/s, u' = 0 m/s

Therefore,

0 = mv+m'v'

-mv = m'v'................ Equation 2

make v the subject of the equation

v = -m'v'/m............. Equation 3

Given: m = 45 kg, m' = 7.65 kg, v' = 20.9 m/s

Substitute into equation 3

v = 7.65(20.9)/45

v = -3.553 m/s

Hence the speed of the skater = 3.553 m/s

(b) F = mgμ..............Equation 4

But F = ma

Therefore,

ma = mgμ

a = gμ............... Equation 5

Where a = acceleration of the skater, g = acceleration due to gravity, μ = coefficient of kinetic friction

Given: μ = 0.03, g = 9.8 m/s²

Substitute into equation 5

a = 0.03(9.8)

a = 0.294 m/s²

Using the equation of motion,

v² = u²+2as............. Equation 6

Where s = distance moved by the skater.

note that u = 0 m/s.

therefore,

v² = 2as

s = v²/2a................ Equation 7

Given: v = 3.553 m/s, a = 0.294

Substitute into equation 7

s = 3.553²/(2×0.294)

s = 12.62/0.588

s = 21.46 m

Answer:

The dimension of mass can be represented as:  [tex][F^{1} T^{1} V^{-1} ][/tex]

Explanation:

We have  Force = Mass X Acceleration

                           = Mass X [tex]\frac{Change in Velocity}{Time Taken}[/tex]

                or, Mass  = Force x [tex]\frac {Time Taken } { Change in Velocity }[/tex]

                             So, dimensions of mass  = [tex]\frac{[F][T]}{[V]}[/tex]

                                                                       = [tex][F^{1} T^{1} V^{-1} ][/tex]

Answer:

53.3micro meters

Explanation:

See attached file

Answer:

f1 / f2 = n2 / n1  

Explanation:

To solve this problem, we should remember that the formula for index of refraction is defined as:

n = c / v

or

n v = c

Where,

n = index of refraction

c = speed of light

v = speed of light in the medium

Since speed of light is constant, then we can simply equate the materials 1 and 2:

n1 v1 = n2 v2

Where the speed of light in the medium (v) can be expressed as:

v = w * f

Where,

w = wavelength of light

f = frequency of light

Therefore substituting this back into the relating equation:

n1  w1 f1 = n1  w2 f1

Since it is given that the light is monochromatic, w1 = w2, this further simplifies the equation to:

n1 f1 = n2 f2

f1 / f2 = n2 / n1                  (ANSWER)

Answer:

The drag coefficient of the car is 0.189

Explanation:

mass of the car = 2250 kg

Frontal area of the car  = 2.35 m^2

initial speed of the car = 72 km/hr = (72 x 1000)/3600 = 20 m/s

final speed of the car = 54 km/hr = (54 x 1000)/3600 = 15 m/s

time taken by the car to slow down = 105 sec

We'll assume that the value of the drag coefficient is constant throughout the deceleration.

The car decelerates from 20 m/s to 15 m/s in 105 seconds, the deceleration is calculated from

[tex]a = \frac{v-u}{t}[/tex]

where a is the deceleration

v is the final speed of the car

u is the initial speed of the car

t is the time taken to decelerate.

imputing values, we'll have

[tex]a = \frac{15-20}{105}[/tex] = -0.0476 m/s^2  (the -ve sign indicates a deceleration, which is a negative acceleration)

we can safely ignore the -ve sign in other calculations that follows

The force (drag force) with which the air around the decelerates the car is equal to..

[tex]F_{D} = ma[/tex]

where [tex]F_{D}[/tex] is the drag force

m is the mass of the car

a is the deceleration of the car

imputing values, we'll have

[tex]F_{D} = 2250*0.0476[/tex] = 107.1 N

equation for drag force is

[tex]F_{D} = \frac{1}{2}pAC_{D} v^{2}[/tex]

where p is the air density ≅ 1.225 kg/m³

A is the frontal area of the car

[tex]C_{D}[/tex] is drag coefficient of the car

v is the relative velocity of air and the car, and will be taken as the initial velocity of the car before starting to decelerate.

imputing these values, we'll have

[tex]107.1 = \frac{1}{2}*1.225*2.35*C_{D}*20^{2}[/tex] = 575.75[tex]C_{D}[/tex]

[tex]C_{D}[/tex] = 107.1/575.75 = 0.189

Answer:

  n = 2.0686

Explanation:

When an unpolarized ray of light is reflected on a surface, the reflected ray is partially polarized, complete polarization occurs when it is true that between the transmitted and reflected ray one has 90, the relationship is

        n = so tea

 let's calculate

        n = tan 64.2

        n = 2.0686

Answer:

Maybe

Explanation:

Tbh it’s different for every women. Most women would say yes because having a bush is a bit disturbing for some and/or could be in return for a women shaving down there (if they do)

Answer:

A.ENERGY: Radio<microwaves<infrared<visible light<ultraviolet<xrays<gammarays

B. WAVELENGTH: Radio>microwaves> infrared>visible light>ultraviolet>xray> gammarays

C. FREQUENCY: Radio<microwaves<infrared<visible light<ultraviolet<xray< gammarays

Explanation:

THIS IS BECAUSE OF THE FOLLOWING EQUATIONS

1.ENERGY (E)= hX freqency

So as energy of radiation increases frequency also increases

2. Velocity (v) = wavelength x frequency

So as wavelength increases frequency decreases and vice versa

Answer:

Explanation:

The rod will act as pendulum for small oscillation .

Time period of oscillation

[tex]T=2\pi\sqrt{\frac{l}{g} }[/tex]

angular frequency ω = 2π / T

= [tex]\omega=\sqrt{\frac{g}{l} }[/tex]

b )

ω = 20( given )

velocity = ω r = ω l

Let the maximum angular displacement in terms of degree be θ .

1/2 m v ² = mgl ( 1 - cosθ ) ,

[ l-lcosθ is loss of height . we have applied law of conservation of mechanical energy .]

.5 (  ω l )² = gl( 1 - cos θ )

.5 ω² l = g ( 1 - cosθ )

1 - cosθ  = .5 ω² l /g

cosθ = 1 - .5 ω² l /g

θ can be calculated , if value of l is given .

Answer:

Explanation:

Here potential energy lost = mgh

h = L ( 1 - cos 46 ) where L is length of rope

= 2.6 x ( 1 - cos 46 )

PE lost = 20 x 9.8 x 2.6 ( 1 - cos 46 )

= 155.6 J

gain of kinetic energy = loss of PE

1/2 m v² = 155.6

.5 x 20 x v² = 155.6

v² = 15.56

v = 3.94 m /s