Electrical equipment in an office takes a current of 13 A from a 240 V supply.
Estimate the cost per week of electricity if the equipment is used for 30 hours each
week and 1 kWh of energy costs Rm0.50​

Answer:

D. Hydrogen combines with oxygen to form water.

Explanation:

Hydrogen combining with oxygen to form water is a typical example of chemical reaction.

During a chemical reaction, atoms of elements are rearranged. Most chemical reactions obey the law of conservation of mass which states that "matter is neither created nor destroyed in a chemical reaction but atoms are simply rearranged".

The other choices given are nuclear reactions. In such reactions, atoms are not rearranged but are simply destroyed and made in the process.

Answer:

D.) Hydrogen combines

Explanation:

BE HAPPY

Answer:

the second pendulum ( also called the royal pendulum) o.994m (39.1 in) long, in which each swing takes one second, became widely used in quality clocks.

Answer: the required mass is 1.7628 × 10²⁵ μ

Explanation:

Given that;

energy released in the fission of one ²³⁵U₉₂ is 206.6 MeV

power p = 28.7 Mega Watts = 28.7 × 10⁶ W = 28.7 × 10⁶/ 1.6× 10⁻¹³ = 17.9375 × 10¹⁹ MeV/s

now fission need per second will be;

⇒ power / energy released i  fission

= 17.9375 × 10¹⁹ MeV /  206.6 MeV = 8.68 × 10¹⁷ per second

now fission need per day will be;

⇒ ( 8.68 × 10¹⁷ × 360 × 24 ) = 7.5 × 10²² per day

hence mass of ²³⁵U₉₂ that is consumed in one day in this reactor will be;

⇒ (235 × 7.5 × 10²²)μ

= 1.7628 × 10²⁵ μ

Therefore the required mass is 1.7628 × 10²⁵ μ

Answer: 1.88 m/s

Explanation:

The speed of the boy moving around a circular park of radius 6 m and taking time 20 seconds is 1.88 m/s.

Speed is a measurement of how quickly an object's distance traveled changes. Speed is a scalar, which implies it has magnitude but no direction as a unit of measurement.

A thing that moves quickly and with great speed, covering a lot of ground in a short time. On the other hand, a slow-moving object traveling at a low speed covers a comparatively small distance in the same amount of time.

Given information:

The radius of the circular park, r = 6 m,

The time is taken to cover one round, t = 20s,

The total distance covered by the boy is equal to the circumference of the park, so

d = 2[tex]\pi[/tex]r,

[tex]d = 2*3.14*6\\d = 37.68 m[/tex]

Now,

the speed of the boy, s = [tex]37.68/20[/tex] ,

s = 1.88 m/s

Therefore, the speed of the boy moving around a circular park of radius 6 m and taking time 20 seconds is 1.88 m/s.

To know more about speed:

https://brainly.com/question/13074982

#SPJ2

Answer:

B) In the near-ultraviolet

Explanation:

The best option to this problem is : In the near-ultraviolet

Answer:

Explanation:

Answer:

by determining the wavelength of the light emitted

Explanation:

The composition of the hot vaporized materials of an asteroid can be find out by the wavelength of the light emitted when the fragment material is burnt out.

Some of the asteroids that are very large do not burn completely in the atmosphere and they fall on the surface of the earth. Thus there is a possibility of radioactivity. An atom is radioactive or unstable when the forces that constitutes the nucleus are not balanced and then the nucleus have excess of energy. Thus these unstable and highly energetic nucleus will try to attain stability by ejecting protons and neutrons, or by releasing gamma rays, beta particles or positrons, etc. Thus they will radiate energy and will cause radioactivity.

Answer:

   ω = ω₀ + α t

      ω² = ω₀² + 2 α  θ

      θ = θ₀ + ω₀ t + ½ α t²

Explanation:

Rotational kinematics can be treated as equivalent to linear kinematics, for this change the displacement will change to the angular displacement, the velocity to the angular velocity and the acceleration to the angular relation, that is

     x → θ

     v → ω

     a → α

with these changes the three linear kinematics relations change to

      ω = ω₀ + α t

      ω² = ω₀² + 2 α  θ

      θ = θ₀ + ω₀ t + ½ α t²

where it should be clarified that to use these equations the angles must be measured in radians

Answer:

Object A

Explanation:

The object that would make you feel worse if you're hit by it is the object possessing the highest momentum. Thus, we need to find the momentum of the two objects.

Momentum of an object is the product of its mass and that of it's velocity. Momentum is given by the formula

P = M * V, where

P = momentum

M = mass of the object

V = velocity of the object

Now, solving for object A, we have

P(a) = 1.1 * 10.2

P(a) = 11.22 kgm/s

And then, solving for object B, we have

P(b) = 2 * 5

P(b) = 10 kgm/s

The object when the highest momentum is object A, and thus would make you feel worse when hit by it

Answer:

Lemon slices is the correct answer

Answer:

food coloring

Explanation:

i think food coloring is because it's just water with food coloring and that's it

Answer:

2.753*10^-11N

Explanation:

According to Newton's law of gravitation, the force between the masses is expressed as;

F = GMm/d²

M and m are the distances

d is the distance between the masses

Given

M = 3.71 x 10 kg

m = 1.88 x 10^4 kg

d = 1300m

G = 6.67 x 10-11 Nm²/kg

Substitute into the formula

F = 6.67 x 10-11* (3.71 x 10)*(1.88 x 10^4)/1300²

F = 46.52*10^(-6)/1.69 * 10^6

F = 27.53 * 10^{-6-6}

F = 27.53*10^{-12}

F = 2.753*10^-11

Hence the gravitational force between the asteroid is 2.753*10^-11N

Answer:

155.17N.

Explanation:

The magnitude of the net force is expressed as;

F = mv²/r where;

m is the mass

v is the velocity of the airplane

r is the radius of the loop

Given

m = 95kg

v = 70m/s

r = 3km = 3000m

Required

Magnitude of the net force

F = 95*70²/3000

F = 95*4900/3000

F = 95*49/30

F = 4655/30

F = 155.17N

Hence the magnitude of the net force on the 95 kg pilot at the bottom of this loop is 155.17N.

The net force on the pilot is 1551.67 N.

Force can be defined as the product of mass and acceleration.

To calculate the magnitude of the net force at the bottom of the loop, we use the formula below.

Formula:

Where:

From the question,

Given:

Substitute these values into equation 1

Hence, the net force on the pilot is 1551.67 N.

Learn more about force here: https://brainly.com/question/13370981

Answer:

the answer is below

Explanation:

The diagram of the problem is given in the image attached.

Mass of rod AB = (0.4 m + 0.4 m) * 3 kg/m = 2.4 kg

Mass of rod OC = (1.5 m) * 3 kg/m = 4.5 kg

Mass of plate = 10 kg/m²[ (π* 0.3²) - (π* 0.1²)] = 2.513 kg

The center of mass is:

[tex]\hat{y}[2.4+2.513+4.5]=(0.75*4.5)+(2.513*0.5)\\\\\hat{y}=0.839\\\\I_{AB}=\frac{1}{12}*2.4*(0.4+0.4)^2= 0.128\ kg/m^2\\\\I_{OC}=\frac{1}{12}*4.5*(1.5)^2= 3.375\ kg/m^2\\\\I_{Gplate}=\frac{1}{2}*(\pi*0.3^2*10)*(0.3)^2-\frac{1}{2}*(\pi*0.1^2*10)*(0.1)^2= 0.126\ kg/m^2\\\\I_{plate}=I_{Gplate}+md^2=0.126+2.513(1.8^2)=8.27\ kg/m^2\\\\I_o=I_{plate}+I_{AB}+I_{OC}\\\\I_{o}=0.128+3.375+8.27=11.773\ kg/m^2 \\\\I_G=I_o-m_{tot}\hat{y}^2\\\\I_G=11.773-(9.413*0.839^2)\\\\I_G=5.147\ kg/m^2[/tex]

(sorry something wrong w my keyboard so write each line for the explnation!)

63.0 m

Explanation:

Acceleration of car

=

v

−

u

t

=

0 ms

−

1

−

21.0 ms

−

1

6.00 s

=

−

3.50 ms

−

2

S

=

v

2

−

u

2

2a

S

=

(

0 ms

−

1

)

2

−

(

21.0 ms

−

1

)

2

2

×

−

3.50 ms

−

2

S

=

63.0

m

Answer:

clouds are created when water vapor and invisible gas turns into water droplets and these water droplets form tiny particles like dust and float in the air.

you have cumulus

cirrus

cirrostraus  

Explanation:

Answer:

true

Explanation:

Answer: The height of the cliff is 104.59 m

Explanation:

The horizontal speed of the car when it leaves the cliff is 13 m/s, and it hits the ground 60m from the shoreline.

Here we can use the relationship:

Time*Speed = Distance.

To find the time that the car is in the air, we know that:

speed = 13m/s

distance = 60m

time = T

13m/s*T = 60m

T = (60m)/13m/s = 4.62 s

This means that the car is falling for 4.62 seconds.

Now let's analyze the vertical problem.

As the car leaves the cliff, it only has horizontal velocity, this means that the vertical initial velocity will be zero

The only force acting in the vertical axis is the gravitational force, this means that the acceleration will be equal to the gravitational acceleration, which is:

g = 9.8m/s^2

then:

a = -9.8m/s^2

Where the negative sign is because the acceleration is pulling the car downwards.

To get the vertical velocity, we could integrate over time to get:

v(t) = (-9.8m/s^2)*t + v0

Where v0 is the constant of integration and the initial vertical velocity, that we already know that is equal to zero, then the vertical velocity as a function of time can be written as:

v(t) = (-9.8m/s^2)*t

To get the vertical position equation, we need to integrate again over the time:

P(t) = (1/2)*(-9.8m/s^2)*t^2 + H

Where H is the constant of integration and the initial vertical position, then H will be the height of the cliff.

We know that the car needs 4.62 seconds to hit the ground, this means that:

P(4.6s) = 0m

Then:

P(t) = (1/2)*(-9.8m/s^2)*(4.62s)^2 + H = 0

            (-4.9m/s^2)*(4.62s)^2 + H = 0

          H =  (4.9m/s^2)*(4.62s)^2 = 104.59 m

This means that the cliff is 104.59 meters high

Answer: the required height is 2.5 m

Explanation:

given the given data in question

Lime to come in rest;

using S = ((U1 + U2)/2) t

⇒ 0.5 = ((√(2gh) + 0)/2) t

t = (0.5 × 2) / √(2gh)

now fat = impulse = change in momentum dp

F = 5mg = dp/dt = [(m√(2gh))/(0.5 × 2)] × √(2gh)

5mg = 2mgh/(0.5 × 2)

5 = h / 0.5

h = 5 × 0.5

h = 2.5 m

Therefore the required height is 2.5 m

Answer:

No they just orbit the sun

Explanation:

Answer:

20kg

Explanation:

Given parameters:

Force  = 100N

Acceleration  = 5m/s²

Unknown:

Mass  = ?

Solution:

According to Newton's second law of motion:

 Force  = mass x acceleration;

 So;

          Mass  = [tex]\frac{force }{acceleration}[/tex]  

          Mass  = [tex]\frac{100}{5}[/tex]   = 20kg

Answer:

inonic bond has greatest difference in electronegativiru

The type of bond that has elements with the greatest difference in electronegativity ionic bond. The correct option is is B.

Electronegativity is a chemical property that describes an atom's or functional group's tendency to attract electrons toward itself.

An atom's electronegativity is affected by both its atomic number and the distance between its valence electrons and the charged nuclei.

Electronegativity is a measurement of an atom's proclivity to attract electrons (or electron density) towards itself.

It governs the distribution of shared electrons between two atoms in a bond. The greater an atom's electronegativity, the more strongly it attracts electrons in its bonds.

Ionic bonds are formed by elements with large differences in electronegativity. Covalent bonds are formed between atoms of elements with similar electronegativity.

Thus, the correct option is B.

For more details regarding electronegativity, visit:

https://brainly.com/question/17762711

#SPJ2

Answer:

0.15 nm

Explanation:

d = Distance between the atomic planes

m = Order

[tex]\theta_{m}[/tex] = First angle = [tex]45.6^{\circ}[/tex]

[tex]\theta_{m+1}[/tex] = Adjacent angle = [tex]21^{\circ}[/tex]

[tex]\lambda[/tex] = Wavelength = 0.07 nm

From Bragg's relation we know

[tex]2d\cos\theta_{m}=m\lambda[/tex]

[tex]2d\cos45.6^{\circ}=m0.07[/tex]

[tex]2d\cos\theta_{m+1}=(m+1)\lambda[/tex]

[tex]2d\cos21^{\circ}=(m+1)0.07\\\Rightarrow 2d\cos21^{\circ}=m(0.07)+0.07[/tex]

So

[tex]2d\cos21^{\circ}=2d\cos45.6^{\circ}+0.07\\\Rightarrow 2d(\cos21^{\circ}-\cos45.6^{\circ})=0.07\\\Rightarrow d=\dfrac{0.07}{2(\cos21^{\circ}-\cos45.6^{\circ})}\\\Rightarrow d=0.14962\ \text{nm}[/tex]

The distance between the atomic planes is 0.15 nm.

Answer:

8 joules

Explanation:

Just did it

Answer:

8 J

Explanation:

Potential energy = mass x gravitational field strength x height

Gravitational field strength is accelerations due to gravity which is 9.8m/s² ( you can round it up and take 10 as well)

Mass = Force ÷ Acceleration

20 ÷ 9.8 = 2.04

Potential energy = 2.04 x 9.8 x 0.40

= 7.99 = 8 J

Answer:

1832

Explanation:

From;

Δp Δx = h/4π

Δp = uncertainty in momentum

Δx = uncertainty in position

h= Plank's constant

But p =mv hence, Δp= Δmv

m= mass, v= velocity

mass of electron = 9.11 * 10^-31 Kg

Mass of proton = 1.67 * 10^-27 Kg

since m is a constant,

Δv = h/Δxm4π

For proton;

Δv = 6.6 * 10^-34/4 * 3.14 * 1.67 * 10^-27 * 1 * 10^-10

Δv = 315 ms-1

For electron;

Δv = 6.6 * 10^-34/4 * 3.14 * 9.11 * 10^-31 * 1 * 10^-10

Δv = 577000 ms-1

Ratio of uncertainty of electron to that of proton = 577000 ms-1/315 ms-1= 1832

Answer:

2.4s

Explanation:

The length of the pendulum = 75ft

Diameter d = 12 inches

The time period of the pendulum is given as

T = 2pi(L/g)^1/2

Then the time it takes to move from displacement to equilibrium is given as:

t = T/4

= (Pi/2)*(L/g)^1/2

= pi/2 x [(75x0.3048)/9.81]^0.5

= 1.57x[22.86/9.81)^0.5

= 2.4s

2.4 seconds is the least amount of time that it would take.

Answer:

The force of friction required to keep the car from sliding down the hill is 898.054 newtons and since [tex]f<f_{max}[/tex], the car will not slide down the hill.

Explanation:

The free body diagram is included below and now we prepare each equation of equilibrium for respective orthogonal axis:

[tex]\Sigma F_{x'} = f-m\cdot g \cdot \sin \theta = 0[/tex] (1)

[tex]\Sigma F_{y'} = N-m\cdot g \cdot \cos \theta = 0[/tex] (2)

Where:

[tex]f[/tex] - Static friction force, measured in newtons.

[tex]N[/tex] - Normal force from the inclined hill to the car, measured in newtons.

[tex]m[/tex] - Mass of the car, measured in newtons.

[tex]g[/tex] - Gravitational constant, measured in meters per square second.

[tex]\theta[/tex] - Angle of inclination of the hill, measured in sexagesimal degrees.

If we know that [tex]m = 1500\,kg[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex] and [tex]\theta = 3.5^{\circ}[/tex], then the friction force required to keep the car from sliding down the hill is:

[tex]f = m\cdot g \cdot \sin \theta[/tex]

[tex]f = (1500\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)\cdot \sin 3.5^{\circ}[/tex]

[tex]f = 898.054\,N[/tex]

The force of friction required to keep the car from sliding down the hill is 898.054 newtons.

If the car does not slide down the hill, then the following condition must be observed:

[tex]f\le \mu_{s}\cdot m\cdot g \cdot \cos \theta[/tex] (2)

Where [tex]\mu_{s}[/tex] is the static coefficient of friction, dimensionless.

If we know that [tex]\mu_{s} = 0.45[/tex], [tex]m = 1500\,kg[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex] and [tex]\theta = 3.5^{\circ}[/tex], then the maximum allowable static friction force is:

[tex]f_{max} = \mu_{s}\cdot m \cdot g \cdot \cos \theta[/tex]

[tex]f_{max} = (0.45)\cdot (1500\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)\cdot \cos 3.5^{\circ}[/tex]

[tex]f_{max} = 6607.378\,N[/tex]

Since [tex]f<f_{max}[/tex], the car will not slide down the hill.

Answer:

[tex]a_{c} = 13.46\ m/s^2[/tex]

Explanation:

The motion of the tethered ball around the pole can be modeled as uniform circular motion. The acceleration of the objects executing uniform circular motion is due to the change in direction of their velocity. This is called centripetal acceleration. It is given by the following formula:

[tex]a_{c} = \frac{v^2}{r}[/tex]

where,

ac = centripetal acceleration = ?

v = speed of ball = 3.5 m/s

r = distance of ball from center of rotation = 0.91 m

Using these values in equation, we get:

[tex]a_{c} = \frac{(3.5\ m/s)^2}{0.91\ m}\\\\a_{c} = 13.46\ m/s^2[/tex]

Answer:

4.4 min

Explanation:

To solve this, we use the law of conservation of momentum

0 = -m(a).v(a) + m(c).v(c), where

m(a) = mass of the astronaut

m(c) = mass of the camera

v(a) = velocity of the astronaut

v(c) = velocity of the camera

Making v(a) subject of the formula, we have

v(a) = m(c).v(c)/m(a)

Now, we make one last assumption, that the astronaut is moving at constant speed and time, thus the time needed will be

t = s/v -> since s = vt

Now, we already have our v from above, so we substitute

t = s/[m(c).v(c)/m(a)]

t = s.m(a)/m(c).v(c)

Applying the values, we have

t = (41.4 * 70.1) / (0.916 * 12)

t = 2902.14 / 10.992

t = 264 seconds or 4.4 minutes