Answer:
90.8%
Explanation:
efficiency = output / input
Simply just put in what we know.
386/425 = 0.908 (Rounded too 3 s.f)
And if you want this in percentage, you simply x100 your answer. Hence the answer being 90.8%
what is unit of pressure?why is it called a derived unit ? give reasons
Answer:
Unit of pressure is pascal (Pa)
The SI-derived unit of measurement for pressure. The pascal is one newton (an SI-derived unit itself) per square meter.
I will be so thankful if u answer correctly!!
(a) 10N
Explanation:The sketch of the two cases has been attached to this response.
Case 1: The box is pushed by a horizontal force F making it to move with constant velocity.
In this case, a frictional force [tex]F_{r}[/tex] is opposing the movement of the box. As shown in the diagram, it can be deduced from Newton's law of motion that;
∑F = ma -------------------(i)
Where;
∑F = effective force acting on the object (box)
m = mass of the object
a = acceleration of the object
∑F = F - [tex]F_{r}[/tex]
m = 50kg
a = 0 [At constant velocity, acceleration is zero]
Substitute these values into equation (i) as follows;
F - [tex]F_{r}[/tex] = m x a
F - [tex]F_{r}[/tex] = 50 x 0
F - [tex]F_{r}[/tex] = 0
F = [tex]F_{r}[/tex] -------------------(ii)
Case 2: The box is pushed by a horizontal force 1.5F making it to move with a constant velocity of 0.1m/s²
In this case, the same frictional force [tex]F_{r}[/tex] is opposing the movement of the box.
∑F = 1.5F - [tex]F_{r}[/tex]
m = 50kg
a = 0.1m/s²
Substitute these values into equation (i) as follows;
1.5F - [tex]F_{r}[/tex] = m x a
1.5F - [tex]F_{r}[/tex] = 50 x 0.1
1.5F - [tex]F_{r}[/tex] = 5 ---------------------(iii)
Substitute [tex]F_{r}[/tex] = F from equation (ii) into equation (iii) as follows;
1.5F - F = 5
0.5F = 5
F = 5 / 0.5
F = 10N
Therefore, the value of F is 10N
Lucas pushes on a car stuck in a ditch with a force of 1000 N for 15 minutes. The car remains stuck. How much work did Lucas do?
Your answer:
O 66.7)
0 0
o 1.22)
O 22,000
Answer:
I think it would be the second answer...
Explanation:
Hope this helps!
Lucas do a work of 0 joule. Hence, option (B) is correct.
What is work?The notion of work in science is significantly different from what it is understood to entail in ordinary life. Every time work is performed, energy is transmitted, as shown by the definition of work in physics.
A force must be applied and there must be movement in the force's direction for a work to be completed scientifically. Having said that, we may state that The product of the component of the force acting in the displacement's direction and its magnitude is work.
Mathematically work done can be expressed as:
work done = force × displacement × cosθ
Where θ is the angle between the force and the displacement .
Here, the car remains stuck, that means, no displacement happens. So. Lucas do a work of 0 joule.
Learn more about work here:
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A capacitor with a capacitance of 50µf when connected to a battery of 400 V. The charge and energy stored on it is? a. 0.05 C and 5 J b. 0.05 C and 10 J c. 0.02 C and 4 J d. 0.08 C and 12 J
Answer:
c. 0.02 C and 4 J
Explanation:
Applying,
Q = CV................ Equation 1
Where Q = Charge, C = Capacitance of the capacitor, V = Voltage.
From the question,
Given: C = 50 μF = 50×10⁻⁶ F, V = 400 V
Substitute these values into equation 1
Q = (50×10⁻⁶)(400)
Q = 0.02 C.
Also Applying
E = CV²/2............. Equation 2
Where E = Energy stored.
Therefore,
E = (50×10⁻⁶ )(400²)/2
E = 4 J
Hence the right option is c. 0.02 C and 4 J
Henry mixed salt and water together in a cup until he observed a clear solution. He measured the mass of the solution. Then he placed the cup outside for several sunny days during the summer. After a week, he observed that only solid salt remained in the cup and the mass had decreased. Henry concluded that a physical and chemical change occurred in this investigation.
Which statements correctly defend or dispute his conclusion?
He is correct. Dissolving salt in water is a physical change, but evaporating the water is a chemical change. Formation of a solid is evidence that a chemical change occurred.
He is correct. Evaporation is a physical change, but dissolving salt in water is a chemical change. The change in mass is evidence that a chemical change occurred.
He is incorrect. Dissolving salt in water and evaporation of the water are both physical changes. The reappearance of salt is evidence that the change was reversible by a physical change, so it could not be a chemical change.
He is incorrect. Dissolving salt in water and evaporation of the water are both chemical
Answer:
He is incorrect. Dissolving salt in water and evaporation of the water are both physical changes. The reappearance of salt is evidence that the change was reversible by a physical change, so it could not be a chemical change.
Answer:c
Explanation:
The atomic mass of calcium is 40.08. What is the mass of 6.02 × 1023 atoms of calcium?
Answer:
It is 40.08 g
Explanation:
[tex]6.02 \times 10 {}^{23} \: atoms = 1 \: mole = 40.08 \: g[/tex]
Calculate the momentum of a 4,800 kg car with a velocity of 25 m/s.
Answer:
p = 120000 kg · m/s
Explanation:
p = mv
p=momentum
m=mass
v=velocity
p = (4800)(25)
p= 120000 kg · m/s
Answer:
[tex]momentum = mass \times velocity \\ = 4800 \times 25 \\ = 120000 \: kgm {s}^{ - 1} [/tex]
Which of the motion variables is the same in both thex and y axis?
A) velocity
B) acceleration
C) time
D) displacement
Answer:
Acceleration (b) not sure tho
Explanation:
IF YOU ANSWER I WILL MARK YOU BRAINLIEST
PPLLSSS
Answer:
the mushrooms
mushrooms are decomposers because they break down organic material around them.
The total momentum before a collision is___to the total momentum after a collision
Answer:
Equal
Explanation:
The law of conservation of energy states that the total momentum before and after a collision are equal
Answer:
Equal to the total momentum of the two objects after the collision.
Which property of the coating on fiber-optic strands makes light visible only at the ends of the strands?
reflectivity
absorbency
transparency
translucency
The answer is A, Hope this helps and sorry for being late :)
Figure 1.18 shows an oscillating pendulum. If the time taken for the pendulum to swing from A to C to B is 3 s, what is the period of the pendulum?
Answer:
a
Explanation:
6. Which of the following graphs correctly demonstrates the relationship between the
electromagnetic force and distance between charges?
Answer:
But where are the graphs
Coulomb's Law describes the relationship between electromagnetic force and the distance between charges.
What is the relationship between electromagnetic force and the distance between charges?The relationship between electromagnetic force and the distance between charges is described by Coulomb's Law, which states that the force between two charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them. Mathematically, Coulomb's Law is expressed as:
F = k (q₁x q₂) / r²
where F is the electromagnetic force, q1 and q2 are the charges, r is the distance between the charges, and k is the Coulomb constant.
This means that as the distance between two charges increases, the force between them decreases, and as the distance decreases, the force increases. The relationship between force and distance is inverse square, which means that the force decreases rapidly as the distance increases.
To know more about electric charges follow
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The A string of a violin is a little too tightly stretched. Beats at 4.00 per second are heard when the string is sounded together with a tuning fork that is oscillating accurately at a concert A (400Hz). What is the period of the violin string oscillations
Answer:
[tex]T=2.5*10^{-3}s[/tex]
Explanation:
From the question we are told that:
Beat frequency [tex]F_b=4[/tex]
Frequency [tex]F=400Hz[/tex]
Generally the equation for Frequency of the violin is mathematically given by
[tex]f_v=F_b+F[/tex]
[tex]f_v=4+400Hz[/tex]
[tex]f_v=404Hz[/tex]
Therefore the period of the violin string oscillations is
[tex]T=\frac{1}{f_v}[/tex]
[tex]T=\frac{1}{404}[/tex]
[tex]T=2.5*10^{-3}s[/tex]
que función cumple en la red las antenas o varillas en la red
Answer:
Explanation:
Para qué sirven las antenas que se colocan en la red
Las antenas de voleibol, también llamadas varillas, sirven para delimitar la zona de juego. Normalmente la red de voleibol es un poco más ancha que la zona de juego, es por ello que las varillas de voleibol se utilizan para demarcar el área de juego.
"" describe about black hole ""
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When a shopping cart rolls into a parked car on the street, It hits the car with a force of 220 newtons. The shopping cart experiences a force from the car that is how many newtons?
Answer:
220 N
Explanation:
When a shopping cart rolls into a parked car on the street, it hits the car with a force of 220 newtons.
We need to find the force the shopping cart experiences from the car.
We know that, Newton's third law of motion states that for every action there is an equal and opposite reaction.
Hence, the shopping cart experiences a force of 220 N from the car.
the refractive index of rock salt with respect to water is 1.17. What will be the refractive index of water with respect to rock salt
Answer:
1.17
Explanation:
Given that,
The refractive index of rock salt with respect to water is 1.17.
We need to find the refractive index of water with respect to rock salt.
We know that,
Refractive index = (speed of light in air or vaccum)/( speed of light in that medium)
Refractive index of rock salt with respect to ice = (speed of light in ice)/(speed of light in rock salt)
The speed of light in ice = c/1.31
The speed of light in rock salt = c/1.54
Required refractive index,
[tex]\mu=\dfrac{1.54}{1.31}\\\\=1.17[/tex]
So, the refractive index of water with respect to rock salt is equal to 1.17.
When a car velocity is negative and its acceleration is negative, what is happening to the cars motion?
Answer:
The car is speeding up in a negative direction.
Explanation:
(02.06)plz help me 20 points
Answer:
the answer is 80 degrees
Explanation:
What is shunt resistance?
How does it help in measuring current?
Answer: A shunt is a low-ohm resistor that can be used to measure current. ... The entire current flows through the shunt and generates a voltage drop, which is then is measured. Using Ohm's law and the known resistance, this measurement can then be used to calculate the current (I = V/R).
find out the speed of the car from home to school in meters per second.
Time - 15 mins
Distance - 8 km
1.875
Explanation:
speed = distance moved ÷ time taken
A body at rest or moving with uniform velocity will have acceleration equals
to:
A.
1
B.
0
C.
Negligible
D.
Infinity
Answer:
B:O
Explanation:
As acceleration is the rate of change of velocity with time, if velocity is uniform, there will be no change in it and acceleration will be zero.
can anyone help me with this question
Answer:
6650km
Explanation:
Distance = (6.4 × 10³ + 250) km
= 6650 km
A 8.6*10^ -6 C charge is places 1.00 m away from a 2.3 * 10 ^ - 4 * C charge. How large is the force of repulsion between the two charges?
Answer:
The force of repulsion is 17.802 N
Explanation:
Given;
magnitude of the first charge, q₁ = 8.6 x 10⁻⁶ C
magnitude of the second charge, q₂ = 2.3 x 10⁻⁴ C
distance between the two charges, r = 1 m
The force of repulsion is calculated using Coulomb's law;
[tex]F = \frac{Kq_1q_2}{r^2} \\\\F = \frac{9\times 10^9 \times 8.6\times 10^{-6} \times 2.3\times 10^{-4}}{1^2} \\\\F = 17.802 \ N[/tex]
Therefore, the force of repulsion is 17.802 N
What the answer to the three of them ill mark brainlest
lhormmia masng ies igentetel
Explanation:
True Or False? Stars glow because they produce energy by the process of nuclear fission.
Answer:
yes is the correct snswer
Explanation:
hope this help
PLS HELPP HURRYYY
The trapdoor swings open and the ball falls to the ground. The ball does not bounce when it hits the ground. Show that the final speed of the ball at the instant before it hits the ground is about 5 m/s.
Answer:
5 m/s
Explanation:
As the ball falls to the ground, it is acted upon by a force which is due to the gravitational force. Hence, the ball falls with an acceleration called the acceleration due to gravity.
Let us assume that the acceleration due to gravity (g) = 10 m/s², Since initially, the body was at rest, hence the initial velocity (u) = 0 m/s. The height to the ground (h) = 1.3 m. Hence using the equation of motion, the final velocity (v) is:
v² = u² + 2gh
Substituting:
v² = 0² + 2(10)(1.3)
v² = 26
v = √26 = 5
v = 5 m/s
According to the theory of plate tectonics, the lithosphere is separated into sections that are called tectonic plates. These plates move in different directions in response to the forces in Earth’s mantle beneath them. Which of the following correctly matches the plate movement with its description?
convergent boundary; plates move away from one another causing rift valleys and the formation of new crustal material
transform boundary; plates slide past one another in opposite directions causing the formation of faults and earthquakes
divergent boundary; as the plates come together gravity pushes the edge of one plate underneath the edge of a neighboring plate
subduction zone; as the plates come together increased pressure causes the plates to fault and fracture leading to the formation of mountains
Answer:
The correct answer is - transform boundary; plates slide past one another in opposite directions causing the formation of faults and earthquakes.
Explanation:
If the continental or oceanic plates slide past one another either in the same direction or in opposition direction forms the transform fault boundary. Due to this tectonic plate formation, no new crust is formed or subducted, but earthquake activities forms.
Convergent boundaries forms by pushing the edge of one plate underneath the other while coming together whereas plates move away from one another causing rift valleys called divergent boundary.
For a specific volume of 0.2 m3/kg, find the quality of steam if the absolute pressure is (a) 40 kPa and (b) 630 kPa. What is the temperature of each case?
Answer:
[tex]x=0.0498[/tex]
[tex]x'=0.659[/tex]
Explanation:
Specific Volume [tex]V=0.2m_3/kg[/tex]
Absolute Pressure (a) [tex]P_a= 40kpa[/tex]
Giving
[tex]T_a=75.87[/tex]
[tex]v_f=1.265*10^{-3}m^3/kg[/tex]
[tex]v_g=3.993m^3/kg[/tex]
(b) [tex]P_a= 630kpa[/tex]
Giving
[tex]T_b=160.13C[/tex]
[tex]v_f'=1.10282*10^{-3} m^3/kg[/tex]
[tex]v_g'=0.30286 m^3/kg[/tex]
(a)
Generally the equation for quality of Steam X is mathematically given by
[tex]x=\frac{v-v_f}{v_g-v_f}[/tex]
[tex]x=\frac{0.2-1.0265*10^{-3}}{3.993-1.0265*10^{-3}}[/tex]
[tex]x=0.0498[/tex]
(b)
Generally the equation for quality of Steam X is mathematically given by
[tex]x'=\frac{v-v_f'}{v_g'-v_f'}[/tex]
[tex]x'=\frac{0.2-1.10*10^{-3}}{3.30-1.1*10^{-3}}[/tex]
[tex]x'=0.659[/tex]
