Answer:
Data:
D = 2400 kg/m³
V = 0.20 m³
M = ?
∴ Density = [tex]\frac{Mass}{Volume}[/tex]
2400 kg/ = [tex]\frac{Mass}{0.2 m^{3} }[/tex]
Mass = 2400 kg/m³ × 0.20 m³
Mass = 480 kg (answer)
Answer:
Therefore, the mass of the block is 480 kg.
Write the dimension of a / b in the x = at + bt2. Where x is the distance and t is the time?
The dimension of a/b where x is the distance and t is the time is T
Given the expression
x = at + bt²
where
x is the distance
t is the time
Based on the homogeneity principle, the expression on the left-hand side must be equal to that on the right. Hence;
x = at
[tex]a = \frac{x}{t}[/tex]
Since x is the distance and distance is measured in metres, the dimension equivalent will be the length 'L'
Since t is the time and time is measured in seconds, the dimension equivalent will be the seconds 'T'
[tex]a=\frac{L}{T}[/tex]
Similarly;
x = bt²
[tex]b=\frac{x}{t^2}\\b=\frac{L}{T^2}[/tex]
Next is to get a/b;
[tex]\frac{a}{b} = \frac{L}{T} \div \frac{L}{T^2}\\\frac{a}{b} = \frac{L}{T}*\frac{T^2}{L} \\\frac{a}{b} =\frac{T^2}{T}\\\frac{a}{b} =T[/tex]
Hence the dimension of a/b is T
A particular electric car is supplied with 300 kJ of chemical energy by the battery. Of this, a total of 70.5 kJ of energy is wasted as heat.
Calculate the overall efficiency of the electric car.
Supplied energy=300kJ
Wasted energy=70.5JUsed energy:-
[tex]\\ \sf\longmapsto 300-70.5=229.5kJ[/tex]
We know
[tex]\boxed{\sf Efficiency=\dfrac{Used\:Energy}{Supplied\:Energy}\times 100}[/tex]
[tex]\\ \sf\longmapsto Efficiency=\dfrac{229.5}{300}\times 100[/tex]
[tex]\\ \sf\longmapsto Efficiency=\dfrac{229.5}{3}[/tex]
[tex]\\ \sf\longmapsto Efficiency=76.5\%[/tex]
The overall efficiency of the electric car = 76.5 %
To find the efficiency the given values are:
Energy supplied = 300 kJ
Energy wasted = 70.5 kJ
Define efficiency and calculate the value of efficiency.In the system the output energy is compared to the input energy is known as efficiency. That can be written as percentage ratio of output energy to the input energy.
Formula of efficiency is,
Efficiency = ( E out / E in ) × 100
Here, Energy supplied = 300 kJ
so, energy used = Energy supplied - Energy wasted
= 300 - 70.5
= 229.5 kJ
Thus, substituting E out = 300 kJ , E in = 229.5 kJ
Efficiency = ( 229.5 / 300 ) ×100
= 229.5 / 3
= 76.5
Hence, The overall efficiency of the electric car is 76.5 %
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Resistivity of metallic wire
depends on *
It's length
It's shape
It's thickness
Nature of material
Answer:
nature of the material
hope this help you
6.
For a given prism the angle of incidence is changed from 0° and 90', the angle of deviation [ ]
b) decreases
c) first decreases and then increases
d) first increases and then decreases
a) increases
Answer:
increase
Explanation:
please mark as brainlyest
Answer
A.Increses
Explanation:
Which type of reactions usually happens slowest?
Answer:
option b is correct..................
calculate the potential energy stored in a meta ball of mass of 80 kg kept at a height of 15m from the earth surface . What will be the potential energy when the metal ball is kept on the earth surface Take (g- 9.8 m/s]
Answer:
11760 J
Explanation:
cuz potential engery is PE = MHG
SO 80×15×9.8= 11760 J
Answer:
11769j
Explanation:
here,
mass(m)=80 kg
height(h)=15m
acceleration due to gravity(g)=9.8m/s^2
now,
potential energy = m×g×h
= 80×9.8×15
= 11760j
What is the total distance covered during its complete motion? (CCT TYPE) *
2 points
350 km
20/3 km
50 km
40/3 km
What is the SI unit of speed? ( CCT type) *
2 points
m/s
mm/s
m/ss
None of the above
. In which period is the bus decelerating? (CCT type) *
2 points
0-5 min
8- 12 min
11-19 min
5-10 min
Only answer who knows, don't spam. because I am in hurry.
Answer:
40/3
M/s
11-19
These are the answers
An object moving north with an initial velocity of 14 m/s accelerates 5 m/s2 for 20 seconds. What is the final velocity of the object?
39 m/s
90 m/s
114 m/s
414 m/s
Answer:
option C
Explanation:
Final velocity of the object is 114 m / s. Hence, final velocity of the object is 114 m / s.
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12. C
13. A
14. B
15. D
16. D
17. B
The sky is blue because: Select one: a. the index of refraction for air is slightly larger for blue than for red b. atomic hydrogen is blue c. air molecules tend to polarize light along a horizontal axis d. oxygen and nitrogen molecules are small compared to the wavelengths of visible light e. oxygen molecules have a lower energy ground state than nitrogen molecules
Answer:
a. the index of refraction for air is slightly larger for blue than for red
What is the voltage of the power source if a motor with a resistance of 20 2 draws a
current of 1.5 A?
Answer:
190v I believe
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A water heater marked 4 kW takes 4 minutes to heat 1 kg of water from 20 °C to 50 °C. The cost of electrical energy per kWh
is $0.120. What will be the total cost of energy consumption?
The total cost of the energy consumption for the given time period is $0.0364
The given parameters include;
power rating of the heater, P = 4 kW = 4000 Wtime taken to completely boil the water,[tex]t = 4 \min = 4 \min \times \frac{1 \ h}{60 \ \min} = 0.067 \ h[/tex]mass of the water, m = 1 kginitial temperature of the water, t₁ = 20 ⁰Cfinal temperature of the water, t₂ = 50 ⁰Cspecific heat capacity of water, c = 4200 J/kg⁰Ccost of electrical energy = $0.12The total energy consumed in the process of heating the water;
Total electrical Energy = Energy of the heater (kWh) + Energy of the heated water (kWh)
Energy of the heater (kWh) = power x time
= 4 kW x 0.067 h
= 0.268 kWh
Energy of the heated water (J) = mcΔt
where;
Δt is the change in temperature = t₂ - t₁
= 50 ⁰C - 20 ⁰C = 30⁰C
Energy of the heated water (J) = 1 x 4200 x 30
= 126,000 J
Electrical power of the heated water (Watts) = [tex]\frac{126,000 \ J}{4 \ \min} \times \frac{1 \min}{60 \ s} = 525 \ W[/tex]
Energy of the heated water (kWh) = [tex]\frac{525}{1000} \times 4\min\times \frac{1 \ hr}{60 \min} = 0.035 \ kWh[/tex]
Total electrical Energy = 0.268 kWh + 0.035 kWh
= 0.303 kWh
The total cost of the energy consumed is calculated as;
[tex]Total \ cost = \frac{\$ \ 0.12}{kWh} \times 0.303 \ kWh = \$ \ 0.0364[/tex]
Therefore, the total cost of the energy consumption is $0.0364
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Starting from rest, two skaters push off against each other on smooth level ice, where friction is negligible. One is a woman and one is a man. The woman moves away with a velocity of 1.9 m/s relative to the ice. The mass of the woman is 46 kg, and the mass of the man is 88 kg. Assuming that the speed of light is 3.0 m/s, so that the relativistic momentum must be used, find the recoil velocity of the man relative to the ice.
resistances is inversely proprtional to___of the conductor
Answer:
resistances is inversely proportional to the area of cross section of the conductor
Explanation:
The resistance of a wire is directly proportional to its length and inversely proportional to its cross-sectional area.
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what is the definition of unit?definition of unit?
Answer:
The Reference standard with which we carry out the measurement of any physical quantity of the same kind is know as unit .
I HOPE I HELP YOU.
Answer:
The standard quantity which is used for the comparison with an unknown quantity is called unit.
Unit is a known or standard quantity in terms of which other physical quantities are measured.
for examples;kilogram,metre,second,etc.
Explanation:
hope it helps you
Enample: the motion of moon around the earth Describe the motion of an object in which its speed constant but the velocity is changing
Answer:
To summarize, an object moving in uniform circular motion is moving around the perimeter of the circle with a constant speed. While the speed of the object is constant, its velocity is changing. Velocity, being a vector, has a constant magnitude but a changing direction.
Explanation:
Speed refers to how fast an object is moving. It can be thought of as the rate at which an object covers distance.
Velocity refers to the rate at which an object changes its position. If you picture a person moving rapidly - one step forward and one step back- always returning to the original starting position, the speed is very rapid, but the velocity is zero. Because the person always returns to the original position, this motion would bébé result in a change in position. Since velocity is defined as the rate at which the position changes, this motion results in zero velocity. To maximize velocity, every effort must be made to maximize the amount an object is displaced from its original position. Every movement should be moving the object further from where it started. Velocity is DIRECTION AWARE. When evaluating the velocity of an object, you have to keep track of direction. This is one of the essential differences between speed and velocity: speed does not keep track of direction, while velocity is directionally aware.
So, when the moon moves around the Earth, the speed remains constant, but since it's moving in an elliptical orbit, it's direction is constantly changing.
Observe the given figure and find the the gravitational force between m1 and m2.
Answer:
The gravitational force between m₁ and m₂, is approximately 1.06789 × 10⁻⁶ N
Explanation:
The details of the given masses having gravitational attractive force between them are;
m₁ = 20 kg, r₁ = 10 cm = 0.1 m, m₂ = 50 kg, and r₂ = 15 cm = 0.15 m
The gravitational force between m₁ and m₂ is given by Newton's Law of gravitation as follows;
[tex]F =G \cdot \dfrac{m_{1} \cdot m_{2}}{r^{2}}[/tex]
Where;
F = The gravitational force between m₁ and m₂
G = The universal gravitational constant = 6.67430 × 10⁻¹¹ N·m²/kg²
r₂ = 0.1 m + 0.15 m = 0.25 m
Therefore, we have;
[tex]F = 6.67430 \times 10^{-11} \ N \cdot m^2/kg \times \dfrac{20 \ kg\times 50 \ kg}{(0.1 \ m+ 0.15 \ m)^{2}} \approx 1.06789 \times 10^{-6} \ N[/tex]
The gravitational force between m₁ and m₂, F ≈ 1.06789 × 10⁻⁶ N
Please help have due very soon?thank you
solve two questions under inclined plane using Newton 2nd law
Explanation:
If the mass of the inclined plane is large enough, could N ever be equal to mgcosθ. Reasons?
So far I've come up with: mgcosθ−N=ma meaning if N were to equal mgcosθ, ma=0. Since the surfaces are frictionless and since N is acting on the inclined plane too(it'll have a horizontal component), this isn't possible. Am I right? Where am I going wrong?
can someone please help me with a and b? what do they mean by amplitude?
Explanation:
first answer is that the to and fro movement of a pendulum is known as amplitude
If the resistance reading on a dmm’s meter face is 22.5 ohms and the range selector switch is set to the R x 100 range what’s the actual measured resistance of the circuit
A.22.5 kohms
B.2.25 mohms
C.2.25 kohms
D.225 ohms
Answer:
c
Explanation:
Calculate the upthrust on a object immersed in water if the object displace water of mass 2 kg.(g=9.8m/s²)
Thrust is force
Mass=2kgAcceleration due to gravity=g=9.8m/s^2Using Newtons Second law
[tex]\boxed{\sf Force=Mass\times Acceleration}[/tex]
[tex]\\ \qquad\quad\sf{:}\dashrightarrow Thrust=2(9.8)[/tex]
[tex]\\ \qquad\quad\sf{:}\dashrightarrow Thrust=19.6N[/tex]
We have that the the upthrust on a object immersed in water is
[tex]U=19.6N[/tex]
From the Question we are told that
mass= 2kg
Gravity g=9.8m/s^2
Generally the equation for the upthrust is mathematically given as
[tex]U=mg[/tex]
Therefore
[tex]U=2*9.8[/tex]
[tex]U=19.6N[/tex]
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The word ‘radiation’ is used to describe particles or waves that are emitted by an object (known as a ‘source’) and carry energy. Name two types of radiation other than nuclear radiation. For each type, name one source of that type of radiation.
Answer:
The word ‘radiation’ is used to describe particles or waves that are emitted by an object
In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes: electromagnetic radiation, such as radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and gamma radiation (γ)
Explanation:
There are four major types of radiation: alpha, beta, neutrons, and electromagnetic waves such as gamma rays. They differ in mass, energy and how deeply they penetrate people and objects.
The first is an alpha particle. These particles consist of two protons and two neutrons and are the heaviest type of radiation particle. Many of the naturally occurring radioactive materials in the earth, like uranium and thorium, emit alpha particles
The second kind of radiation is a beta particle. It's an electron that is not attached to an atom. It has a small mass and a negative charge. Tritium, which is produced by cosmic radiation in the atmosphere and exists all around us, emits beta radiation. Carbon-14, used in carbon-dating of fossils and other artifacts, also emits beta particles. Carbon-dating simply makes use of the fact that carbon-14 is radioactive. If you measure the beta particles, it tells you how much carbon-14 is left in the fossil, which allows you to calculate how long ago the organism was alive.
The third is a neutron. This is a particle that doesn't have any charge and is present in the nucleus of an atom. Neutrons are commonly seen when uranium atoms split, or fission, in a nuclear reactor. If it wasn't for the neutrons, you wouldn't be able to sustain the nuclear reaction used to generate power.
The last kind of radiation is electromagnetic radiation, like X-rays and gamma rays. They are probably the most familiar type of radiation because they are used widely in medical treatments. These rays are like sunlight, except they have more energy. Unlike the other kinds of radiation, there is no mass or charge. The amount of energy can range from very low, like in dental x-rays, to the very high levels seen in irradiators used to sterilize medical equipment.
show how three identical 6 resistors must be connected tho have the following effective resistance values 9 and 4 ohms
Answer:
connect two 9 ohms resistance in series now it becomes 18 ohm
The pressure at the ice point for a constant-volume gas thermometer is 4.81 x 10^4Pa.
While that at the steam point is 6.48 x 10^4 Pa.
What pressure would the thermometer indicate at 50°c?
Answer:
0 deg C = 4.81E4 pressure at 0 deg
100 deg C = 6.48E4 pressure at steam point
100 deg C - 50 deg C = (6.48 - 4.81) * 10^4 = 1.67E4 Pa
50 deg C = 50 / 100 * 1.67E4 + 4.81E4 = 5.65E4 Pa Just the halfway point between the two given pressures
A car has a mass of 2000 kg. While it is traveling along a perfectly flat road, it goes around an unbanked turn that has a radius of 40.0 m. The coefficient of static friction between the car tires and the road is 0.500. The car travels successfully around the turn at a constant speed of 10.0 m/s. Calculate the magnitude of the car's acceleration as it goes around the turn. _______ m/s^2
Answer:
2.5 m/s²
Explanation:
The given parameters are;
The mass of the car, m = 2,000 kg
The radius of the car, r = 40.0 m
The coefficient of friction between the car tires and the road, μ = 0.500
The constant speed with which the car moves, v = 10.0 m/s
The normal reaction of the road on the car, N = The weight of the car;
∴ N = m × g
Where;
g = The acceleration due to gravity ≈ 9.81 m/s²
N ≈ 2,000 kg × 9.81 m/s² = 19,620 N
The frictional force, [tex]F_f[/tex] = μ × N
The centripetal force, [tex]F_c[/tex] = m·v²/r
The car moves without slipping when [tex]F_f[/tex] = [tex]F_c[/tex]
Therefore, [tex]F_f[/tex] = 0.500 × 19,620 N = 2,000 kg × [tex]v_{max}[/tex]²/40.0 m
∴ [tex]v_{max}[/tex] = √(0.500 × 19,620 N × 40.0 m/2,000 kg) ≈ 14.007 m/s
Therefore, the velocity with which the car moves, v < [tex]v_{max}[/tex]
The cars centripetal acceleration, [tex]a_c[/tex] = v²/r
∴ [tex]a_c[/tex] = (10.0 m/s)²/40.0 m = 2.5 m/s²
The cars centripetal acceleration as it goes round the turn, [tex]a_c[/tex] = 2.5 m/s².
The radius of the base of a wooden cylinder 2m and its altitude is 7m. What is its mass?
Answer:
88 m ^2
Explanation:
One possible unit of speed is
Answer:
option d
Explanation:
Meter per second
Suppose high tide is at midnight, the water level at midnight is 3 m, and the water level at low tide is 0.5 m. Assuming the next high tide will occur 12 hours later (at noon), find the time, to the nearest minute, when the water level is at 1.125 m for the second time after midnight.
We have that the time, to the nearest minute, when the water level is at 1.125 m for the second time after midnight is
[tex]t=10.0hours[/tex]
From the Question we are told that
Maximum height [tex]h_{max}=3m[/tex]
Minimum height [tex]H_{min}=0.5m[/tex]
Time for next high tide will occur[tex]T=12 hours =>720 min[/tex]
Generally Average Height
[tex]h_{avg}=\frac{3+0.5}{2}\\\\h_{avg}=1.75[/tex]
Therefore determine Amplitude to be
[tex]A=h_{max}=j_{avg}\\\\A=3-1.75\\\\A=1.25[/tex]
Generally, the equation for Time is mathematically given by
At t=0
[tex]h(x)=Acos(Bx)+h_{avg}[/tex]
Where
[tex]B=\frac{2\pi}{P}\\\\B=\frac{2\pi}{720}\\\\B=8.73*10^{-3}[/tex]
Therefore
[tex]h(t)=Acos8.73*10^{-3}(t)+h_{avg}[/tex]
Hence the Time at [tex]T=1.125[/tex] is
[tex]1.125(t)=1.25cos(8.73*10^{-3})(t)+1.75[/tex]
[tex]-0.1249t=1.75[/tex]
[tex]t=10.0hours[/tex]
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Why do scientists not use US customary units when reporting their data?
One of the scientist's jobs is to report the results of his experiments to all the other scientists in the world.
There isn't a single real science shop anywhere in the world that uses the US customary system of units. Not one.
Even in the measly three countries that use it for measuring carpet, pumping gas, and weighing fish ... Myanmar, Liberia, an the USA ... the scientists do their work in the SI/MKS/metric system.
