Answer:
3 ohms
Explanation:
Applying,
R₁₀₀ = R₀(1+αΔT).............. Equation 1
Where α = coefficient of resistance, ΔT = change in temperature, R₁₀₀ and R₀ = Resistance at 100°C and 0°C respectively
make R' the subject of the equation
R₀ = R₁₀₀/(1+αΔT).............. Equation 2
From the question,
Given: R₁₀₀ = 4.2 ohm, α = 0.004 per degree, ΔT = 100-0 = 100°C
Substitute these values into equation 2
R₀ = 4.2(1+0.004×100)
R₀ = 4.2/1.4
R₀ = 3 ohms
Đặt điện áp U = 200 cos Omega t vào hai đầu đoạn mạch gồm biến trở R và tụ điện mắc nối tiếp điều chỉnh r để công suất tiêu thụ của đoạn mạch đạt cực đại Khi Điện áp tức thời hai đầu r = 100 V và đang tăng thì điện áp tức thời giữa hai đầu đoạn mạch là
Answer:
I don't understand the Question
Brass is made by melting a mixture which contain 67% by mass of copper and 33% by mass of zinc if no change in volume.Calculate the density of brass
Answer:
The density of brass is approximately 8,261.73 kg/m³
Explanation:
The percentage composition by mass of brass is given as follows;
The percentage by mass of copper = 67%
The percentage by mass of zinc = 33%
The density of copper, ρ₁ = 8.96 g/cm³
The density of zinc, ρ₂ = 7.133 g/cm³
Therefore, where we have, m = 100 g of brass, we have;
The mass of copper, m₁ = 67 g
The volume of copper, V₁ = m₁/ρ₁
∴ V₁ = 67 g/(8.96 g/cm³) ≈ 7.47767857 cm³
The volume of zinc, V₂ = m₂/ρ₂
∴ V₂ = 33 g/(7.133 g/cm³) ≈ 4.62638411 cm³
The volume of the brass, V = V₁ + V₂
V = 7.47767857 cm³ + 4.62638411 cm³ ≈ 12.104 cm³
The density of brass, ρ = m/V
∴ ρ = 100 g/(12.104 cm³) ≈ 8.26 g/cm³
The density of brass, ρ ≈ 8.26 g/cm³ = 8,261.73 kg/m³
HELPPP THIS IS IMPORTANT NOWW OMGG HELPPPP PLEASEE
Answer:
The correct answer is -
19 - C) parasitism
20- B) commensalism
Explanation:
Parasitism is a type of symbiotic relationship among two different organisms where one is benefited and the other is harmed. The harmed organism known as the host and the benefitted organism called the parasite. For instance, tapeworms are parasites in the human body.
Commensalism is also a symbiotic relationship but in this relationship, one symbiont is benefitted but another one neither benefitted nor harmed. For instance, Hermit crabs use the shells of dead snails for homes.
A exerted by an object on another is a force
hope this helps
Answer:
If a person is pushing a desk across the room, then there is an applied force acting upon the object. The applied force is the force exerted on the desk by the person.
A stone is thrown vertically upward with an initial velocity of 40m/s. Taking g = 10 m/s^2 find the maximum height reach by the stone and what is the net displacement and distance covered by the stone.
Explanation:
u=40
v=?
h=?
v²-u²=2gs
0²-40²=2×10×s
160=20s
s=160/20
=80m/s
total distance= upward distance ×downward distance
=80+80
=160m
total displacement=0 because u and v is the same.
Answer:
The maximum height is 80 m and the total distance covered by the stone is 160 m and the displacement is zero.
Explanation:
Final velocity v = 0
Initial velocity u = 40m/s
We know that,
Using equation of motion
[tex]v^{2} =u^{2} +2gh[/tex]
[tex]0-40^{2} =2[/tex] × [tex]10[/tex] × [tex]h[/tex]
The maximum height is:
[tex]h=80[/tex] [tex]m[/tex]
The stone will reach at the top and will come down
Therefore, the total distance will be:
[tex]s=h_{1} +h_{2}[/tex]
[tex]s=80m-80m=160m[/tex]
The net displacement is:
[tex]D=h_{1} -h_{2}[/tex]
[tex]D=80m-80m=0[/tex]
Hence, The maximum height is 80 m and the total distance covered by the stone is 160 m and the displacement is zero.
hope this helps.....
If velocity is Hositive, which would most likely yield a negative acceleration?
O A final velocity that is faster than an initial velocity.
O A time that is less than a half hour.
O An initial velocity that is faster than a final velocity.
O A time that is greater than a half hour.
Answer:
A final velocity that is faster than an initial velocity.
Explanation:
The acceleration of an object is given by :
[tex]a=\dfrac{v-u}{t}[/tex]
Where
v is final velocity and u is initial velocity
t is time taken
If the final velocity is more than the initial velocity, the acceleration is positive. So, the correct option is (a).
DO U KNOW CARRYMINATI
If a charge of 40kC flows through an electrical heater and the amount of energy converted into heat is 10MJ. Calculate the potential difference across the ends of the heater.
Answer:
Energy Transfer Quiz - Quiz
The diagram shows a heater above a thermometer. The thermometer bulb is in the position shown.
An object is sitting on the floor. A 22.4 N force is pulling the object to the right and an 11 N force is pulling the object to the left. The gravitational force on the object is 70 N. What is the net force?
answer = 33.4 net force.
A student starts at position (4,4) m and undergoes three displacements:
d1 = (2, -3) m, d2 = (-5, 0) m, and d3 = (1, 6) m.
What is the final position of the student? Show your solution graphically and numerically.
please help!!
Answer:
The final position is (2, 7)m
Explanation:
When we work with coordinate pairs, the addition works as:
(a, b) + (c, d) = (a + c, b + d)
So, for example, if we start at (a, b), and we have a displacement d = (1, 1)
we just need to solve:
(a, b) + (1, 1) = (a + 1, b + 1)
Now, in this case, we start at (4, 4)m
first, we have d1 = (2, -3) m
After this displacement, the position is:
(4, 4)m + (2, -3)m = (4 + 2, 4 - 3)m = (6, 1)m
Now we have a displacement d2 = (-5, 0) m
After this, the position is:
(6, 1)m + (-5, 0)m = (6 -5, 1 + 0)m = (1, 1)m
After this, we have the final displacement d3 = (1, 6) m, so the final position will be:
(1, 1)m + (1, 6)m = (1 + 1, 1 + 6)m = (2, 7)m
Below you can see a rough sketch of the path that the student take, where he/she starts at point A.
Questlon 20 of 20 Which change to an object would quadruple its kinetic energy?
A. Reducing its mass to one-half of its original value
B. Increasing its velocitato twice its original value
C. Reducing its velocity to one-half of its original value O
D. Increasing its mass to twice its original value
Answer:Whenever the velocity of the object increases or usually doubles, the kinetic energy will be quadrupled. If in case you are not familiar with kinetic energy, this is known as the type of energy that is in motion. The greater the mass of the object, the greater the total of the energy
Explanation:
Change to an object would quadruple its kinetic energy Increasing its velocity to twice its original value
What is kinetic energy?
In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes. The same amount of work is done by the body when decelerating from its current speed to a state of rest. Formally, kinetic energy is any term in a system's Lagrangian which includes a derivative concerning time.
In classical mechanics, the kinetic energy of a non-rotating object of mass m traveling at a speed v is [tex]{\textstyle {\frac {1}{2}}mv^{2}}[/tex]
In relativistic mechanics, this is a good approximation only when v is much less than the speed of light.
The standard unit of kinetic energy is the joule, while the English unit of kinetic energy is the foot-pound.
Learn more about kinetic energy
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A car travelling at 30 ms' decelerates
to 10 m sin a distance of 20 m. What
is the deceleration of the motion, in m
s?
Answer:
V²=U² + 2as
Where V=Final Velocity
U=Initial Velocity
a=acceleration ( Deceleration in this case)
s=distance covered
10² = 30² + 2(a)(20)
100 = 900 + 40a
100 - 900 = 40a
-800=40a
a= -800/40
a= -20ms-².
Its negative because the car Decelerated.
a
c) Determine the coefficient of static friction required to produce
net force of 6.0N?
Determine the coefficient of static friction to produce net force of 6.0N?
i think the data is not complete but that's according to me
which type of material is the best sound absorber?
a. glass
b. wood
c. concrete
d. carpet
Explanation:
Glass is the best sound absorber material.
At the local grocery store, you push a 14.5-kg shopping cart. You stop for a moment to add a bag of dog food to your cart. With a force of 12.0 N you now accelerate the cart from rest through a distance of 2.29 m in 3.00 s. What was the mass of the dog food?
Answer:
The mass of the dog food added is 9.03 kg
Explanation:
Given;
mass of the shopping cart, m₁ = 14.5 kg
let the mass of the bag added = m₂
the force applied, F = 12 N
initial velocity of the cart-bag system, u = 0
distance traveled by the system, d = 2.29 m
time of motion of the system, t = 3.0 s
The acceleration of the system is calculated as;
[tex]d = ut + \frac{1}{2} at^2\\\\2.29 = 0 + (\frac{1}{2} \times 3^2)a\\\\2.29 = 4.5 a\\\\a = \frac{2.29}{4.5} \\\\a = 0.51 \ m/s^2[/tex]
The total mass of the system (M) is calculated as follows;
F = Ma
M = F/a
M = (12)/(0.51)
M = 23.53 kg
The mass of the dog food added is calculated as;
m₂ = M - m₁
m₂ = 23.53 kg - 14.5 kg
m₂ = 9.03 kg
Temperature is the average amount of energy of motion in each particle of a substance. It is a measure of how loud or quiet a substance is. true of false
Answer:
fhddjdhdjndvdbhd honcho highchair suck Vicki
what is time write its SI unit
Why is the time period of a charged particle in a uniform magnetic field independent of velocity??
Answer:
time period is independent of K.E of particle, it is inversely proportional to specific charge of the particle and it is independent of angle between velocity and magnetic field
If a girl is running along a straight road with a uniform velocity 1.5 m/s, find her
acceleration in numerical type
Answer:
Explanation:
The definition of acceleration is the change in velocity over a period of time. If the girl's velocity is constant, that means it's not changing. Therefore, acceleration is 0 m/s/s
Kinetic and potential energy are related
a.) indirectly
b.) inversely
c.) directly
d.) Both A and B
Which statement about momentum is false? a. Momentum is a force b. Momentum may be transferred c. Momentum is always conserved d. Momentum is a property only of moving objects
Answer:
So, option(a).
Explanation:
Momentum is the measure of motion of the object.
Momentum is given by the product of mass and the velocity of the object.
(a) It is false.
(b) It is true, momentum is transferred.
(c) It is true, As the momentum of the system is conserved when no external force is applied on the system.
(d) It is true, as the momentum is associated with the velocity of the object.
calculate:An elcetric lamp is rated 240V and 40W. What is the cost of running the lamp for 62 hours if the elctricity authorities charges #2.50k per KWH
Answer:
Total cost = #6.2
Explanation:
Given the following data;
Voltage = 240 V
Power = 40 W
Time = 62 hours
Cost = #2.50
To find the cost of running the lamp for 62 hours;
First of all, we would determine the energy consumption of the electric lamp
Energy consumption = power * time
Energy consumption = 40 * 62
Energy consumption = 2480 Watt-hour = 2.48 Kwh (1 Kilowatts is equal to 1000 watts).
Next, we would determine the cost of running the lamp;
Total cost = energy consumption * cost
Total cost = 2.48 * 2.50
Total cost = #6.2
1. A vehicle of mass 1500 kg braked to a standstill from a
velocity of 24 m/s in 12 s.
i. Show that the deceleration of the vehicle was 2.0 m/s2.
ii. Calculate the resultant force on the vehicle.
Explanation:
i. Vi=24
Vf=0
t= -2
a=vf-vi/t =0-24/12 = -2m/S2
ii. F=ma = 1500×-2= -3000 N
Donald claims that he will always have more momentum than Jason because Donald has twice the mass of
Jason. Is Donald correct? Why or why not?
Answer:he is correct
Explanation: when Donald runs all his weight is moving at the same speed so when all that weight hits a stopped object the weight will transfer its force into that object Kinda like how a truck hits a car
A force of 20000N acts on the raft in the direction down
State the name given to the force shown by arrow in Fig.
Calculate the mass of the raft.
Answer:
Figure is not there
Explanation:
Helpppp!!!
You are sitting on a dock watching water waves as they pass. you noticed at 5 waves to pass by certain spot every 20 seconds you also noticed at the crest of the water line up exactly with two points that are 6 m apart.
A) what is the frequency of these waves?
B)what is the wavelength of the waves described above?
C) what is the velocity of the waves from where u are watching?
Please show ur workkkkk
Answer:
A) 0.25 Hz
B) 6 m
C) 1.5 m/s
Explanation:
The number of waves that pass a certain spot every 20 seconds = 5 waves
The distance between the crest = 6 m
A) The frequency of the wave, f = The number of cycles per second = 5/20 = 0.25 per second = 0.25 Hz
B) The wavelength of the wave, λ = The distance between crests = 6 m
C) The velocity of the wave, v = f × λ = 0.25/s × 6 m = 1.5 m/s.
digestion that takes place in the mouth.
Two wires made of the same material are connected in parallel
across the mains. The length and radius of one wire is two
times that of the other wire. If heat produced in the shorter wire
is 100 J, then the heat produced in the longer wire is:-
O A. 100 J
B. 180 J
O C. 2003
O D. 420 J
Answer:
The heat produced in the longer wire is 200 J.
Explanation:
When the two wires are connected in parallel then the voltage across both the wires is same.
Let the length of the second wire is L and the radius of the second wire is R.
The length of the first ire is 2L and the radius of the first wire is 2R.
Heat produced in the second wire is 100 J.
Let the heat produced in the first wire is H'.
The resistance of the wire is proportional to length of the wire and inversely proportional to the area of the wire.
[tex]\frac{R_2}{R_1}=\frac{L\times \pi\times 4R^2}{2L\times \pi\times R^2}\\\\\frac{R_2}{R_1}=2[/tex]
The heat produced is given by
[tex]H=\frac{V^2}{R}\\\\\frac{H_1}{H_2}=\frac{R_2}{R_1}\\\\\frac{H_1}{100}=2\\\\H_1=200 J[/tex]
1. The mechanical energy of the pendulum at the highest point equals
a. kinetic energy only.
b. kinetic energy x potential energy.
c. potential energy only.
d. zero.
Answer:
c. potential energy only
Explanation:
at highest point the body will having some height and gravitational force will work on it.
since the velocity at highest point will be zero therefore there will no kinetic energy
A car accelerates for 10 seconds. During this time, the angular
velocity of the wheels of the car increases from 10 rad/s to 25 rad/s.
What is the angular acceleration of the wheels during this time?
e
Answer:
the angular acceleration of the car is 1.5 rad/s²
Explanation:
Given;
initial angular velocity, [tex]\omega_i[/tex] = 10 rad/s
final angular velocity, [tex]\omega_f[/tex] = 25 rad/s
time of motion, t = 10 s
The angular acceleration of the car is calculated as follows;
[tex]a_r = \frac{\omega_f - \omega_i }{t} \\\\a_r = \frac{25-10}{10} = 1.5 \ rad/s^2[/tex]
Therefore, the angular acceleration of the car is 1.5 rad/s²