Answer:
0.4 g/cm^3
Explanation:
The density of an object can be found using the following formula.
d= m/v
where m is the mass and v is the volume.
The mass of the metal is 6 grams and the volume is 15 centimeters^3
m=6 g
v= 15 cm^3
Substitute these into the formula.
d= 6 g/ 15 cm^3
Divide 6 g by 15 cm^3 (6/15=0.4)
d= 0.4 g/ cm^3
The density of the metal is 0.4 grams per cubic centimeter.
Density = (mass) / (volume)
Density = (6 g) / (15 cm³)
Density = (6/15) (g/cm³)
Density = 0.4 g/cm³
This 'metal' has less than half the density of water, and it floats on water ! It cannot be of Earthly origin, and must have been dropped here by aliens.
Either that, or else the metal has been hammered and stretched and beaten out and shaped so that it has an artificially large volume ... something like the way sailing ships are made out of thick plates of steel.
1.what are some of the impacts of modern communication in our socio economic life?
2.how is possible to make a call to our relatives residing in other part of country ?explain?
Answer:
The impacts of modern communication in our socio economic life includes;
a) Staying connected
b) Carrying out business transaction
c) Exceeding boundaries
d) Overcoming weakness and disability
e) Reaching out to a wider audience
2. It is possible to make long distant call to our relatives in other part of the country by direct distance dialing (DDD)
Explanation:
The telecommunication service called direct distance dialing allows a caller to make a call to a location outside the area where they are calling without the assistance of an operator. To make a direct dialing call, a subscriber or caller will be required to include extra prefix digits to the original number than for numbers within hers or his particular local area code.
A window washer is standing on a scaffold supported by a vertical rope at each end. The scaffold weighs 210 N and is 2.8 m long. What is the tension in each rope when the 698-N worker stands 1.80 m from one end?
Answer:
The value of tension in the two ropes are 354.2 N and 553.8 N
Explanation:
Find the free body diagram attached below.
For the system to be in mechanical equilibrium, the following conditions have to be satisfied.
1. Upward forces must be equals to the downward forces,
T1 + T2 =210N + 698N
[tex]T1 + T2 =908 ------------------ equation 1[/tex]
2. Clock-wise turning moments = anti-clockwise turning moments
[tex]T1 \times 2.8 = 210N \times 1.4m + 698N\times (2.8 - 1.8)\\2.8T1 =294Nm + 698Nm\\2.8T1 =992Nm\\T1 = \frac{992}{2.8}=354.2 N[/tex]
From this, we were able to evaluate the value of T1 by taking our moments about T2 as the turning point
We can input the value of T1 into equation 1 to give us the value of T2 as
T2 = 908 - T1
T2 = 908 - 354.2N= 553.8 N
There fore, the value of tension in the two ropes are 354.2 N and 553.8 N
Average acceleration. Please help!
Answer:
8.43 m/s²
Explanation:
Average acceleration is the change in velocity over change in time.
a = Δv/Δt
First, convert km/h to m/s.
45 km/h = 12.5 m/s
500 km/h = 138.9 m/s
Now find the acceleration.
a = (138.9 m/s − 12.5 m/s) / 15.0 s
a = 8.43 m/s²
the coefficient of friction between a hard rubber and normal street pavement is 0.8 What is the steepest incline on which a car can be safely parked
Answer:
38.7°
Explanation:
Draw a free body diagram of the car. There are three forces:
Weight force mg pulling down,
Normal force N pushing up perpendicular to the incline,
and friction force Nμ pushing parallel up the incline.
Sum of forces in the perpendicular direction:
∑F = ma
N − mg cos θ = 0
N = mg cos θ
Sum of forces in the parallel direction:
∑F = ma
Nμ − mg sin θ = 0
Nμ = mg sin θ
μ = (mg sin θ) / N
μ = (mg sin θ) / (mg cos θ)
μ = tan θ
Given μ = 0.8:
θ = tan⁻¹(0.8)
θ = 38.7°
ULIULIOL
THIS. AJUSI
A bus is moving with a velocity of 72 km/hr. On seeing the red signal of traffic
at 27 m ahead on the road, the driver applied brakes and the bus stopped at a
distance of 25 m. Calculate the time taken by the car to come at rest. (Ans: 2.5 s)
with
of 60 km/hr. On seeing a child at 11m ahead on
A
a
Answer:
The time taken by the car to come at rest is 2.5 seconds
Explanation:
The parameters given are;
Speed of bus = 72 km/hr
Distance at which bus stopped = 25 m
Given that the speed and the distance covered before stopping are j=known, we have;
v² = u² - 2·a·s
Where:
v = Final velocity = 0
a = Deceleration of the bus
s = Distance covered while decelerating = 23 m
u = Initial velocity = 72 km/hr = 20 m/s
Which gives;
0² = (20 m/s)² - 2×a×25 m
20² = 2×a×25 m
a = 20²/(2×25) = 8 m/s²
The time, t, it takes for the car to come at rest is given by the relation;
v = u - at
0 = 20 - 8×t
t = 20/8 = 2.5 s.
If you hold a bar magnet in each hand and bring your hands together, will the force be attractive or repulsive if the magnets are held:
a) with the two north poles together?
b) with a north pole and south pole together
Answer:
Part A:
They will repel each other because same poles repel each other.
Part B)
They will attract each other because different poles attract each other..
A car of mass 800 kg is moving at a uniform velocity of 72 km/hr. Find its
momentum.
(Ans: 16000 kgm/s)
Answer:
P = 16,000 kgm/s
Explanation:
Given :
Mass = m = 800 kg
Velocity = v = 72 km/hr = 20 m/s
Required :
Momentum = P = ?
Formula:
P = mv
Solution:
P = (800)(20)
P = 16,000 kgm/s
Answer:
Explanation:
Momentum = Mass × Velocity
Mass = 800 kg
Velocity = 72 km/hr = 20 m/s
∴ Momentum = 800 × 20
= 16000 kgm/s
hope this helps
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what causes short sightedness ?how is it corrected
Answer:
Short sight occurs when the eyeball is too long or the lens is too thick, or both. As a result, light rays from distant objects are focused in front of the retina (because the light rays are highly converged). The image formed on the retina is therefore out of focus.
Short sight can be corrected by wearing glasses with concave lenses. Light rays from distant objects are diverged by concave lenses before entering the eyes, so that light can be focused on the retina to form a sharp image.
Which is a negative effect of deforestation on the environment? A. habitat restoration B. desertification C. soil production D. urbanization
Answer:Deforestation refers to the decrease in forest areas across the world that are lost for other uses such as agricultural croplands, urbanization, or mining activities. Greatly accelerated by human activities since 1960, deforestation has been negatively affecting natural ecosystems, biodiversity, and the climate. The UN’s Food and Agriculture Organization estimates the annual rate of deforestation to be around 1.3 million km2 per decade.
Explanation:
The negative effect of deforestation on the environment is desertification. The correct option is B.
What is desertification?Desertification is the process by which fertile land becomes desert, typically as a result of drought, deforestation, and inappropriate agriculture or land use practices. It occurs when land that was once able to support vegetation and life becomes increasingly dry, barren, and unable to sustain crops, livestock, or human populations. This can be due to natural causes such as prolonged droughts, but it is often exacerbated by human activities such as deforestation, overgrazing, and soil degradation. Desertification can have devastating effects on the environment, leading to soil erosion, loss of biodiversity, and reduced productivity of the land. It can also cause social and economic problems, such as displacement of people, food shortages, and conflicts over resources.
Here in the question,
Deforestation is the clearing of trees and other vegetation from an area, leading to the loss of habitat and biodiversity, and disruption of water cycles. It can also cause soil erosion, which can result in the depletion of soil nutrients, reduced productivity, and eventually lead to desertification. Additionally, deforestation contributes to climate change by releasing carbon dioxide into the atmosphere, which can cause global warming and other environmental problems. Habitat restoration, soil production, and urbanization are not negative effects of deforestation but can be impacted by it.
Therefore, The correct answer is B i. e Desertification.
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WILL GIVE BRAINLIEST
The truck had kinetic energy of 72 MJ and came to a stop in 5 metres. Calculate the force exerted by the brakes showing all working
Answer:
The force exerted by the brakes is 14,400,000 N
Explanation:
Initial kinetic energy of truck = 72 MJ
Work done by the breaks, W = Force exerted by the brakes × Distance, D, the truck came to stop
The distance, D, in which the truck came to a stop is given as 5 meters
Given that the initial kinetic energy, KE of the truck that was reduced by the breaks = The work done by the brakes
We have;
W = ΔKE = Change in kinetic energy
ΔKE = Initial kinetic energy - Final Kinetic Energy
Initial kinetic energy, KE = 72 MJ
Final Kinetic Energy = 0 J (Truck stopped)
ΔKE = 72 - 0 = 72 MJ
Therefore we have;
Force exerted by the breaks = W/D = 72 MJ/5 = 14.4 MN. = 14,400,000 N.
If three vectors added together, forms a triangle, the resultant will be equal to twice the vector zero doubled the magnitude none of the above
Answer:
the resultant vector will be a null vector or with 0 magnitude
Explanation:
Just after taking off, the aeroplane continues to accelerate as it gains height. State two forms of energy that increase during this time.
Answer:
The two forms of energy that increase during the time after take off are;
1) The kinetic energy KE
1) The potential energy PE
Explanation:
1) Given that the airplane is accelerating, we have that the velocity, v, of the airplane is increasing, such that the we have the kinetic energy, KE, for a given mass, m, of the airplane increasing as follows;
KE₂ = 1/2×m×v₂² > KE₁ = 1/2×m×v₁²
2) Also, as the height, h, of the airplane increases during the ascent, we have that the potential energy increasing along side as follows;
PE₂ = m × g × h₂ > PE₁ = m × g × h₁
Therefore, the two forms of energy that increase during the time after take off are the kinetic and the potential energy.
If a star is located 100 light years from Earth, what can you conclude about the light from the star?
The light will take 100 years to reach Earth.
The light will take 100 seconds to reach Earth.
The light will take 300,000 years to reach Earth.
The light will travel a total of 300,000 kilometers to reach Earth.
Answer:
Light from star would take 100 years to reach the Earth.
Explanation:
1 light year = speed of light × 1 year
1 light year = 9.46 × 10¹⁵ m
hope i helped
-lvr
Answer:
a
Explanation:
;)
How many different words can be formed with the letters AAAABBCCD (not necessarily meaningful words)?
Answer:
90,720 words
Explanation:
The different ways in which a given number of n things or items can be arranged where all of the items are taken at the same time is known as ⁿPₙ which is the same as n factorial, n!
Therefore, the number of alphabets in the word AAAABBCCD = 9
Hence, the number of different words will exclude words where the 4 A, 2 Bs, and 2 Cs are together, and include the number of ways where the the grouped letters can be arranged among themselves as follows
9! × 4! /(4! × 2! × 2!) = 90,720 words
What is the net force acting on the buggy. ?The net force is pointing to the ?
Answer: 390, right
explanation: The net force is just the sum of all of these forces acting on an object. ... This equation is the sum of n forces acting on an object. The magnitude of the net force acting on an object is equal to the mass of the object multiplied by the acceleration of the object, as shown in this formula.
the net force acting on the buggy is 390 and The net force is pointing to the is right
The following information should be considered:
The net force should be the sum of all of these forces that acted an object.This equation is the sum of n forces acting on an object. The magnitude of the net force acting on an object is equivalent to the mass of the object and multiplied by the acceleration of the objectLearn more: https://brainly.com/question/17961582?referrer=searchResults
a 35g ball is lifted up from 1.0m to 3.0m. How much work is done?
[tex]\mathfrak{\huge{\pink{\underline{\underline{AnSwEr:-}}}}}[/tex]
Actually Welcome to the Concept of the Work And Energy.
So we here use the formula as,
W= Mgh
so after solving we get as,
W = 0.686 Joules
Why do you think four tires of a car can withstand the huge weight of a car?
Explanation:
I think its because when you join the weight of the 4 tyres it could sum up to the weight of the car
Answer:
this is because; as area increases, pressure decreases.
Explanation:
there are four tires in a car and these tires are equally flat, this helps to reduce the force acting upon it and helps to withstand the huge weight of the car.
Please HELP!!! I will give brainliest to whoever gives honest help!!! A 500 kg satellite experiences a gravitational force of 3000 N, while moving in a circular orbit around the earth. Determine the radius of the circular orbit. Determine the speed of the satellite. Determine the period of the orbit.
Given that,
Mass of satellite = 500 kg
Gravitational force = 3000 N
We need to calculate the radius of the circular orbit
Using formula of gravitational force
[tex]F_{g}=\dfrac{GMm}{(R+h)^2}[/tex]
Where, G = gravitational constant
R = radius of earth
h = radius of the circular orbit
M = mass of earth
m = mass of satellite
Put the value into the formula
[tex]3000=\dfrac{6.67\times10^{-11}\times500\times6\times10^{24}}{(6.4\times10^{6})^2+h^2}[/tex]
[tex]h^2=\dfrac{6.67\times10^{-11}\times500\times6\times10^{24}-3000\times(6.4\times10^{6})^2}{3000}[/tex]
[tex]h=\sqrt{\dfrac{6.67\times10^{-11}\times500\times6\times10^{24}-3000\times(6.4\times10^{6})^2}{3000}}[/tex]
[tex]h=5073460.35\ m[/tex]
[tex]h=5.1\times10^{6}\ m[/tex]
(II). We need to calculate the speed of the satellite
Using formula of velocity
[tex]v=\sqrt{\dfrac{GM}{r}}[/tex]
Put the value into the formula
[tex]v=\sqrt{\dfrac{6.67\times10^{-11}\times6\times10^{24}}{5.1\times10^{6}}}[/tex]
[tex]v=8858.36\ m/s[/tex]
[tex]v=8.8\times10^{3}\ m/s[/tex]
[tex]v=8.8\ km/s[/tex]
(III). We need to calculate the period of the orbit
Using formula of time period
[tex]T=2\pi\sqrt{\dfrac{r^3}{GM}}[/tex]
Put the value into the formula
[tex]T=2\pi\sqrt{\dfrac{(5.1\times10^{6})^3}{6.67\times10^{-11}\times6\times10^{24}}}[/tex]
[tex]T=3617.40\ sec[/tex]
[tex]T=1.00\ hr[/tex]
Hence, (I). The radius of the circular orbit is [tex]5.1\times10^{6}\ m[/tex]
(II). The speed of the satellite is 8.8 km/s.
(III). The period of the orbit is 1.00 hr.
A 5000 kg mass rocket “breaks the engine” when it is 100 m high and climbing at a speed of 75 m / s. Calculate:
1) The maximum height it will reach
2) The speed with which it will hit the ground after the fall.
Answer:
1:281.25m
2:75m/s
Explanation:
using the equation
[tex]v^{2} = u^{2} + 2gs[/tex]
at maximum height v is zero so using that you can make s the subject of the formula
[tex]h \: max = u^{2} \div \: 2g[/tex]
so substitute the velocity 75 and the constant g-10m/s^2
as for the returning velocity we say displacement is zero since you go and come back the same distance
so
[tex]v = { + or - }u[/tex]
u is the initial speed in this case it's positive since going in the direction of gravity
Choose the word that keeps the sentence in agreement.
1. The girl
seven years old when she lost her tooth. (was/were)
2. The boy
eight siblings. (have/has)
3. The teacher played
music. (his/he)
4. Michael and Jill asked for
money back. (them/their)
La luz pasa del medio A al medio B formando un ángulo de 35° con la frontera horizontal entre ambos. Si el ángulo de refracción también es de 35°, ?cuál es el índice de refracción relativo entre los dos medios?
Answer:
Índice de refracción entre los dos medios = 1,43
Refractive index between the two media = 1.43
Explanation:
El índice de refracción entre dos medios se explica mejor entendiendo primero la refracción.
Cuando las olas se mueven de un medio a otro, a menudo experimentan un cambio de dirección con respecto al medio en el que viajan.
Por lo tanto, el índice de refracción se expresa como el seno del ángulo de incidencia dividido por el seno del ángulo de refracción.
El seno del ángulo de incidencia y la refracción utilizados en esta fórmula de índice de refracción se miden respectivamente con respecto a la vertical.
En esta pregunta Ángulo de incidencia = 35° a la horizontal = (90° - 35°) a la vertical = 55° a la vertical.
Ángulo de refracción = 35°
Índice de refracción entre los dos medios
= (Sin 55°) ÷ (Sin 35°)
= 0.8192 ÷ 0.5736
= 1.428 = 1.43 a 2 d.p.
¡¡¡Espero que esto ayude!!!
English Translation
The light passes from medium A to medium B at an angle of 35 ° with the horizontal border between the two. If the angle of refraction is also 35 °, what is the relative refractive index between the two media?
Solution
The refractive index between two media is best explained by first understanding refraction.
When waves move from one medium to another, they often experience a change in direction with respect to the medium in which they are travelling.
Hence, refractive index is expressed as the sine of angle of incidence dibided by the sine of angle of refraction.
The sine of angle of incidence and refraction used in this refractive index formula are both respectively measured with respect to the vertical.
In this question,
Angle of incidence = 35° to the horizontal = (90° - 35°) to the vertical = 55° to the vertical.
Angle of refraction = 35°
Refractive index between the two media
= (Sin 55°) ÷ (Sin 35°)
= 0.8192 ÷ 0.5736
= 1.428 = 1.43 to 2 d.p.
Hope this Helps!!!
In the Bohr theory of the hydrogen atom, an electron moves in a circular orbit about a proton, assume the radius of the orbit is 5.29 10-11 m. (a) Find the magnitude of the electric force exerted on each particle.
Answer:
[tex]F=9.06*10^{-8} N[/tex]
Explanation:
We can use the Coulomb force
[tex]F=k\frac{q_{e}q_{p}}{r^{2}}[/tex]
[tex]F=9*10^{9}\frac{|-(1.6*10^{-19})^{2}|}{(5.29*10^{11})^{2}}[/tex]
[tex]F=9.06*10^{-8} N[/tex]
The direction of the force is toward proton with respect to the electron reference coordinate and is in the direction of the electron in the proton system reference.
I hope it helps you!
A bus accelerates at -0.5 m/s2 for 12.5 seconds . If the bus had an initial speed of 31 m/s, what is its new speed? A. 12.25m/s B. 37.25m/s C. 24.75m/s D. 6.25m/s
Answer:
37.5m/s
Explanation:
a=(v-u)/t
0.5 = (v - 31) / 12.5
v - 31 = 0.5 x 12.5
v - 31 = 6.25
V = 6.25 + 31
v = 37.25m/s
Unidirectional current is referred to as _____.
direct current
indirect current
alternating current
electric charge
Answer:
Direct current
Explanation:
Wood has chemical energy, which can be used to generate thermal and radiant energy when burned in a fireplace. Which best explains what happens to the total amount of energy in this scenario?
Answer:In the case of burning wood, stored potential energy (in the form of chemical energy) in the log is released due to heating by other excited atoms. This chemical reaction is called combustion and requires oxygen. Combustion changes the potential chemical energy into kinetic energy in the form of heat.
Explanation:
Answer:
In the case of burning wood, stored potential energy (in the form of chemical energy) in the log is released due to heating by other excited atoms. This chemical reaction is called combustion and requires oxygen. Combustion changes the potential chemical energy into kinetic energy in the form of heat.
Last guy copied off my computer when i left room
Explanation:
A neutral atom has the same number of protons as it does neutrons.
A. True
O B. False
SUBMIT
Answer:
The answer is False
Hope this helps you
It is false that a neutral atom has the same number of protons as it does neutrons. The correct option is B.
The claim that "A neutral atom has the same number of protons as it does neutrons" is untrue. Protons and electrons in a neutral atom are equal in number, but neutron counts can change.
Electrons have a negative charge, whereas protons have a positive charge. A neutral atom has a net charge of zero because the protons' positive charge is balanced by the electrons' negative charge.
Neutrons don't have an electric charge, though. Within a single element, the amount of neutrons can change, giving rise to many isotopes.
Isotopes contain the same amount of protons, but their atomic masses vary depending on how many neutrons they have.
Thus, the correct option is B. False.
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We weigh less in water than in air. Why?
A flat polished area is turned through 15 degrees. If the angle of incidence is 20 degrees, what is the angle between the incident ray and the reflected ray of the turned surface?
Answer:
50°Explanation:
Angle of rotation of the flat polished surface [tex]\theta[/tex] = 15°
angle of incidence i = 20°
Since the polished surface is turned at an angle of 15°, the angle of reflection
r = 2[tex]\theta[/tex] (Note that the angle of rotation only have effect of the angle of reflection)
r = 2*15 = 30°
The angle between the reflected ray and the incident ray will be equal to the sum of the angle of incidence and the angle of reflection i.e i+r
The angle between the reflected ray and the incident ray = 20°+ 30° = 50°
Please help. Brainliest will be given! 25 points. Show all work.
Explanation:
Given:
v₀ₓ = 15 m/s cos 20° = 14.10 m/s
aₓ = 0 m/s²
v₀ᵧ = 15 m/s sin 20° = 5.13 m/s
aᵧ = -9.8 m/s²
t = 1.5 s
Find: Δx and Δy
Δx = v₀ₓ t + ½ aₓ t²
Δx = (14.10 m/s) (1.5 s) + ½ (0 m/s²) (1.5 s)²
Δx = 21.1 m
Δy = v₀ᵧ t + ½ aᵧ t²
Δy = (5.13 m/s) (1.5 s) + ½ (-9.8 m/s²) (1.5 s)²
Δy = -3.33 m
any ss2 here (11th Grade)
Answer:
a) 50°b) 40°Explanation:
Check the complete diagram n the attachment below
a) The angle of incidence on a plane surface is the angle between the incidence ray and the normal ray acting on a plane surface. The normal ray is the ray perpendicular to the surface while the incidence ray is the ray striking a plane surface.
According to the diagram, the angle of reflection r₂ on M₂ is 90°-g where g is the angle of glance.
Given angle of glance on M₂ to be 40°, r₂ = 90-40 = 50°
According the second law of reflection, the angle of incidence = angle of reflection, therefore i₂ = r₂ = 50° (on M₂)
Also ∠OO₂O₁ = ∠OO₁O₂ = 40° (angle of glance on M₁){alternate angle}
The angle of incidence on M₁ = 90° - 40° = 50°
b) The angle of incidence to the surface of M₁(∠PO₁A)will be the angle of glance on M₁ which is equivalent to 40°