b. i. In a hydraulic press, a force of 200N is applied to master piston of area 25cm. If
the press is designed to produce a force of 5000N, determine the area of the slave
piston.
(4marks)
​

ANSWER:

0.4081%

Explanation:

Difference=24.6-24.5=0.1

Relative error = 0.1/24.5*100=0.4081%

Relative error is equal to the = difference between both the values/The true value *100

Answer:

c. Intensity

Explanation:

Wavelength is a distance (meters).

Speed is distance per time (meters / second).

Intensity is power per area (Watts / square meter).

Pitch is frequency (cycles / second).

Answer:

car is moving away its direction is negative.

the speed must also be negative.

speed this distance decreases the acceleration is negative and if the speed is increasing the acceleration is positive.

Explanation:

In the exercise they indicate that the direction to the motion sensor is positive, as they indicate that the car is moving away its direction is negative.

The speed of the car is

           v = (x₂-x₁) / t

As the positions are negative, and the car moves away the speed must also be negative.

The analysis for acceleration must be very careful if the speed this distance decreases the acceleration is negative and if the speed is increasing the acceleration is positive.

Answer:

7.5 Ω

Explanation:

Voltage = Current x Resistance

(V = IR)

240 = 32 R

R = 240 / 32

= 7.5 Ω

Answer: The only advantage cutting crops with a sickle is that its very effective for cutting lodged crops.

Answer:

1. Fleming's left hand rule

2. It must be projected towards the east

Explanation:

Fleming's left-hand rule states that; When a current-carrying conductor is placed in an external magnetic field, the conductor experiences a force perpendicular to both the field and to the direction of the current flow. This rule was first put forward by John Ambrose Fleming in the later part of the nineteenth century.

Hence if the thumb, fore finger and middle finger of the lefthand are held mutually at right angles to each other; the thumb shows the direction of motion, the fore finger shows the direction of the field while the middle finger shows the direction of the current.

Hence, if the alpha particle is projected eastwards(at right angles) to the uniform magnetic field, it will be deflected southwards in the magnetic field.

Answer:

1) a    α,  m   I,  W=F.d    W =τ . θ,

2)  a = v²/r

Explanation:

1) The amounts of rotational and translational motion are related

acceleration is

        a = d²x / dt²

    linear displacement is equivalent to angular rotation, therefore angular acceleration is

      α = d²θ / dt²

force in linear motion is equivalent to moment in endowment motion

       F = m a

       τ = I α

the mass is the inertia of the translation, in rotational motion the moment of inertia is the rotational inertia

          I = m r²

Work is defined by W = F. d

in rotation it is defined by W = τ . θ

The linear momentum is p = mv

the angular momentum L = I w

momentum the linear motion is I = F dt

in the rotation it is I = τ dt

2) The velocity is a vector therefore it has modulus and direction, linear acceleration changes the modulus of velocity, whereas circular motion changes the direction (the other element of the vector).

      [tex]a_{c}[/tex]Ac = v²/r

Answer:

Explanation:

To add or subtract two vectors, add or subtract the corresponding components. Let →u=⟨u1,u2⟩ and →v=⟨v1,v2⟩ be two vectors. The sum of two or more vectors is called the resultant. The resultant of two vectors can be found using either the parallelogram method or the triangle method .

Answer:

Explanation:

We shall apply law of conservation of momentum to know velocity after collision . Let it be v .

total momentum before collision = total momentum after collision

15 x 1.5 - 12 x .75 = ( 15 + 12 ) v

v = .5 m /s

kinetic energy before collision

1/2 x 15 x 1.5² + 1/2 x 12 x .75²

= 16.875 + 3.375

= 20.25 J

kinetic energy after collision

= 1/2 x ( 15 + 12 ) x .5²

= 3.375 J

Loss of energy = 16.875 J

This energy appear as heat and sound energy that is produced during collision .

Answer: b) - 8.0 [tex]m/s^{2}[/tex]

Explanation: Acceleration is a vector indicating a rate an object's velocity changes over time:

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

and its SI unit is [tex]m/s^{2}[/tex]

For the minivan to stop, it takes a period of 0.5s:

a = [tex]\frac{4.0}{0.5}[/tex]

a = 8.0 [tex]m/s^{2}[/tex]

As a vector, acceleration has magnitude (8[tex]m/s^{2}[/tex]) and direction. Since it is stopping, the minivan has a direction opposite to the other car, which means acceleration is negative. So: a = [tex]- 8.0 m/s^{2}[/tex].

Explanation:

momentum = mass x velocity

momentum = 40 x 20 = 800kgm/s

Answer:

800kgm/s

Explanation:

momentum= mass×velocity

= 40×20

= 800kgm/s

Answer:

The minimum riding speed relative to the whistle (stationary) to be able to hear the sound at 21.0 kHz frequency is 15.7  m/s

Explanation:

The Doppler shift equation is given as follows;

[tex]f' = \dfrac{v - v_o}{v + v_s} \times f[/tex]

Where:

f' = Required observed frequency = 20.0 kHz

f = Real frequency = 21.0 kHz

v = Sound wave velocity = 330 m/s

[tex]v_o[/tex] = Observer velocity = X m/s

[tex]v_s[/tex] = Source velocity = 0 m/s (Assuming the source is stationary)

Which gives;

[tex]20 = \dfrac{330- v_o}{330+0} \times 21[/tex]

330 - [tex]v_o[/tex] = (20/21)*330

[tex]v_o[/tex] = 330 - (20/21)*330 = 15.7 m/s

The minimum riding speed relative to the whistle (stationary) to be able to hear the sound at 21.0 kHz frequency = 15.7  m/s.

Answer:

Explanation:

T = 8 s

angular frequency ω = 2π / T

= 2 π / 8

= π / 4

x ( t ) = A ( sinωt + π / 2 ) because initial phase difference is π / 2

= A cos ωt

= A cos π t / 4  

v = Aω sinωt

= 2 x π / 4 sinωt

= .5 π sinπt / 4

when t = 2

v = .5 π sinπ x 2 / 4

= .5 π x 1

= 1.57  cm /s

At t = 3 s

v = .5 π sin π x 3 / 4

= .5 π sin 135°

= .5 π / √ 2

= 1.11 cm /s

Answer:

 K = 9.53 MeV

Explanation:

The kinetic energy that the alpha particle has emitted, is the energy in excess after removing the resting energy of the atoms and the helium nucleus that forms the alpha particle

Since energy and masses are related and cannot be

          m₀ c² = [tex]m_{f}[/tex] c² + m_He c²+ K

          K = c² (m₀ - m_{f} - m_He)

the mass of the Helium atom is 4 u

           K = (3 10⁸)² (211,988868 -207.976652 - 4,002) 1,661 10⁻²⁷

           K = 14,949 10⁻¹¹ (0.0102)

          K = 1,527 10⁻¹² J

let's reduce 1 J = 6,242 10¹² MeV

           K = 9.53 MeV

Answer:

B. A negative particle outside the nucleus

Explanation:

Electrons are very small particles orbiting outside of the nucleus of an atom. They carry negative charges.

The nucleus only contains protons and neutrons. Protons are positive, and neutrons have no charge (i.e. neutral)

Answer:

Increase

Explanation:

Resonance is a phenomenon which occurs when a body A in motion set another body B into motion of it own natural frequency. So for resonance to be minimize in a body is to increase the width to span ratio. So as to reduce the overall vibration which affects directly building resonance, the stiffness or trusses and girders should be increase. The increase in this aspect helps to reinforce building structure and support.

Answer:

λ₀ = 2 d n

Explanation:

A soap film is a layer where the lus is reflected on the surface and on the inside of the film, these two reflected rays can interfere with each other either constructively or destructively.

Let's analyze the general conditions of this interference,

* When the ray of light reaches the surface of the film it is reflected, as the index of refraction of the air is less than the index of the film, the reflected ray has a phase change of 180º

* When the ray penetrates the film, its wavelength changes due to the refractive index of the film.

          λ = λ₀ / n

where lick is the wavelength in the vacuum or air and n index of refraction of the film, in general this interference is observed perpendicular to the film, so the sine veils 1. the expression for constructive interference taking in what previous remains

         2d = (m + ½) λ

the expression for destructive interference remains

         2d = m λ

          2d = m λ₀ / n

When the film is placed on a glass plate whose index of refraction is greater than the index of refraction of the film, in the reflection in the lower part of the film another phase difference of 180º is created, for which we have a difference of total phase of 180 +180 = 360º, which is equivalent to no phase difference, therefore the two previous equations are interchanged.

Therefore where we had destructive interference now a cosntructive interference happens we can see the reflected light.

Find us the wavelength that this constructive interference creates

           2d n = m λ₀

           λ₀ = 2 d n / m

To find the minimum wavelength, suppose we observe the first interference pattern m = 1

         λ₀ = 2 d n

where d is the thickness of the film and n the index of refraction of the same

Answer:

D. AC+BD -> AD +BC

Explanation:

I got it right

A double displacement reaction is also called the double replacement reaction or double decomposition reaction. Here AC + BD → AD + BC is a double displacement reaction. The correct option is D.

A double displacement reaction is defined as a chemical reaction in which the positive and negative ions of two ionic compounds exchange their places to form two new compounds. The general form of a double displacement reaction is given as:

AC + BD → AD + BC

Here 'A' and 'B' are positively charged cations, whereas 'C' and 'D' are negatively charged anions. The double displacement reactions generally occur between the substances in an aqueous solution. In order for a reaction to occur, one of the products is usually a solid precipitate, a gas or a molecular compound like water.

Thus the correct option is D.

To know more about double replacement reaction, visit;

https://brainly.com/question/13870042

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Answer:

[tex]\boxed{ V_{2}= 0.03189 m^3}[/tex]

Explanation:

According to Charles Law

=> [tex]\frac{V_{1}}{T_{1}} = \frac{V_{2}}{T_{2}}[/tex]

Where [tex]V_{1}[/tex] = 0.0279 m³, [tex]T_{1}[/tex] = 280 K and [tex]T_{2}[/tex] = 320 K

=> [tex]\frac{0.0279}{280} = \frac{V_{2}}{320}[/tex]

=> [tex]V_{2}[/tex] = 0.03189 m³

Answer:

Pink - Pluto

Green - Mercury

Red - Mars

Black - Saturn

Blue - Neptune

Yellow - Jupiter

Orange - Jupiter

Milk Color - Venus

Explanation:

The galaxy is full of colors. There are various planets in the galaxy which are different colored. Their color is usually determined by the gases present there. The pink gases present near the Pluto makes Pluto appears to be of magenta or pink colored. The mercury is green colored because it reflects green rays. Mars is called the Red planet because of presence of Martin Rocks there.

Answer:

Explanation:

Films are widely popular and their audio visual nature provides them a pervasive power for social influence. Therefore, they have the potential to play an important role as a medium of entertainment, information and education and as a catalyst for social change. Films are popular because they entertain.

Movies are about sitting in a theatre, watching something- watching a story unfold with people you don't know- watching that happen and emoting an emotion knowing that for those two hours or so, when one walks into that theatre, he/she don't have to worry about what is going on outside.

Answer:

True.

Explanation:

Total internal reflection is bound to occur when light travels from dense medium to less dense.

From the table given in the question above, we obtained:

Refractive Index of Crown glass = 1.52

Refractive Index of Asphalt = 1.635

From the above, Crown glass has a lower refractive index when compared to Asphalt. This means that Crown glass is less dense than Asphalt.

Therefore, total internal reflection will not occur when light travels from Crown glass to Asphalt because Crown glass is less dense than Asphalt.

Answer:

(a) By small angle approximation, we have;

F = -2×T×Δy/l

(b) [tex]The \ frequency \ of \ oscillation, \ f = \dfrac{1}{2\cdot \pi }\cdot\sqrt{\dfrac{2 \cdot T}{l \cdot M} }[/tex]

Explanation:

(a) The diagram shows the mass, M, being restored by two equal tension, T acting on the elastic strings l, such the restoring force, F acts along the path of motion of the mass, with distance Δy

Therefore, the component of the tension T that form part of the restoring force is given as follows;

Let the angle between the line representing the extension of the elastic strings T and the initial position of the string = ∅

Then we have;

String force, [tex]F_{string}[/tex] = T×sin∅ + T×cos∅ + T×sin∅ - T×cos∅  = 2×T×sin∅

Whereby the angle is small, we have;

sin∅ ≈ tan∅ = Δy/l

Which gives;

[tex]F_{string}[/tex] = 2×T×sin∅ = 2×T×Δy/l (for small angles)

Restoring force F = [tex]-F_{string}[/tex] = -2×T×Δy/l

F = -2×T×Δy/l

(b) Given that the the tensions do not change appreciably as the mass, M, oscillates from Δy we have;

By Hooke's law, F = -k×x

Whereby Δy corresponds to the maximum displacement of the mass, M from the rest position, which gives;

Which gives;

F = M×a = -k×Δy

a =  -k×Δy/M

d²(Δy)/dt² =  -k×Δy/M

When we put angular frequency as follows;

ω² = k/M

We get;

d²(Δy)/dt² =  -ω²×Δy

Which gives;

Δy(t) = A×cos(ωt + Ф)

The angular frequency is thus, ω = √(k/M)

Period of oscillation = 2·π/ω = 2·π/√(k/M)

The frequency of oscillation, f = 1/T = √(k/M)/(2·π)

Where:

k = 2·T/l, we have;

f = √(k/M)/(2·π) = √(2·T/l)/m)/(2·π)

The frequency of oscillation is given as follows;

[tex]f = \dfrac{1}{2\cdot \pi }\cdot\sqrt{\dfrac{2 \cdot T}{l \cdot M} }[/tex]

Answer:

S1 = 1/2 g t^2     distance stone falls in time t

S2 = Vy t - 1/2 g t^2   distance thrown stone rises in time t

H = 49 = S1 + S2 = Vy t

t = 49 / 40 sec   time when stones meet

Check:

Stone 1 falls:      1/2 g t^2 = 1/2 * 9.8 * (49 / 40)^2 = 7.35 m

Stone 2 rises :  40 * (49 / 40) - 1/2 * 9.8 (49 / 40)^2 = 41.65 m

Answer:

3.3×10⁻⁹ kg/s

Explanation:

There are two forces on the particle: weight force pulling down and drag force pushing up.  At terminal velocity, the speed is constant, so the acceleration is zero.

∑F = ma

bv − mg = 0

b = mg / v

b = (10⁻¹³ kg) (9.8 m/s²) / (3×10⁻⁴ m/s)

b = 3.3×10⁻⁹ kg/s

Explanation:

(b) We know that,

1 day = 24 hours

1 hour = 3600 s

So, we found that, 1 day = 86400 s

We need to find the 360 days into seconds. So,

1 day = 86400 s

360 days = 86400×360

360 days = 31104000 seconds

(d) Weight of a body, W = 600 N

Acceleration due to gravity on mars is 3.7 m/s²

Weight, W = mg

m is mass of body

[tex]m=\dfrac{W}{g}\\\\m=\dfrac{600}{3.7}\\\\m=162.16\ kg[/tex]

(e) Mass of body, m = 100 kg

Acceleration due to gravity on the moon, 1.6 m/s²

Weight, W = 100 × 1.6

W = 160 N

Answer:

[defined as]

Explanation:

it is the missing word

Answer:

BETTER EXPLANATION

Explanation:

When you drink from a straw, you create a little space of low pressure inside your mouth and in the top of the straw. Then the air outside the straw pushes down on the surface of the drink and forces the liquid up through the straw and into your mouth.

Answer:

88 %

Explanation:

The rate of heat loss by a conducting material of thermal conductivity K, cross-sectional area,A and thickness d with a temperature gradient ΔT is given by

P = KAΔT/d

The total heat lost by the styrofoam wall is P₁ = K₁A₁ΔT₁/d₁ where K₁ =thermal conductivity of styrofoam wall 0.033 W/m-K, A₁ = area of styrofoam wall = 17 m², ΔT₁ = temperature gradient between inside and outside of the wall and d₁ = thickness of styrofoam wall = 0.20 m

The total heat lost by the glass window is P₂ = K₂A₂ΔT₂/d₂ where K₂ =thermal conductivity of glass window pane wall 0.96 W/m-K, A₂ = area of glass window pane = 0.15 m², ΔT₂ = temperature gradient between inside and outside of the window and d₂ = thickness of glass window pane = 7 mm = 0.007 m

The total heat lost is P = P₁ + P₂ = K₁A₁ΔT₁/d₁ + K₂A₂ΔT₂/d₂

Now, since the temperatures of both inside and outside of both window and wall are the same, ΔT₁ = ΔT₂ = ΔT

So, P = K₁A₁ΔT/d₁ + K₂A₂ΔT/d₂

Since P₂ = K₂A₂ΔT₂/d₂ = K₂A₂ΔT/d₂is the heat lost by the window, the fraction of the heat lost by the window from the total heat lost is

P₂/P = K₂A₂ΔT/d₂ ÷ (K₁A₁ΔT/d₁ + K₂A₂ΔT/d₂)

= 1/(K₁A₁ΔT/d₁÷K₂A₂ΔT/d₂ + 1)

= 1/(K₁A₁d₂÷K₂A₂d₁ + 1)

= 1/[(0.033 W/m-K × 17 m² × 0.007 m ÷ 0.96 W/m-K × 0.15 m² × 0.20 m) + 1]

= 1/(0.003927/0.0288 + 1)

= 1/(0.1364 + 1)

= 1/1.1364

= 0.88.

The percentage is thus P₂/P × 100 % = 0.88 × 100 % = 88 %

The percentage of heat lost by window of the total heat is 88 %