Daniel wants to find out if he can notice the difference in light intensity when he adds some lit candles to a set of 50 lit candles. When he adds 5 candles to the set, he notices the difference in intensity half the time. However, when he adds less than 5 candles to his set, he does not notice any difference in the intensity of light. In this scenario, Daniel's difference threshold for detecting the change in light intensity is ________ lit candles.

Complete question:

(b) How much energy must be supplied to boil 2kg of water? providing that the specific latent heat of vaporization of water is 330 kJ/kg. The initial temperature of the water is 20 ⁰C

Answer:

The energy that must be supplied to boil the given mass of the water is 672,000 J

Explanation:

Given;

mass of water, m = 2 kg

heat of vaporization of water, L =  330 kJ/kg

initial temperature of water, t = 20 ⁰C

specific heat capacity of water, c = 4200 J/kg⁰C

Assuming no mass of the water is lost through vaporization, the energy needed to boil the given water is calculated as;

Q = mc(100 - 20)

Q = 2 x 4200 x (80)  

Q = 672,000 J

Q = 672,000 J

Q = 672,000 J

Therefore, the energy that must be supplied to boil the given mass of the water is 672,000 J

Answer:

Mass = 52.63 kilograms

Explanation:

Given the following data;

Acceleration due to gravity = 3.8 m/s²

Weight = 200 N

To find mass;

Mathematically, the weight of a physical object is given by the formula;

Weight = mass * acceleration due to gravity

Substituting into the formula, we have;

200 = mass * 3.8

Mass = 200/3.8

Mass = 52.63 kg

Answer:

Inertia : a property of matter by which it continue in its existing state of rest or uniform motion in a straight line, unless that state is changed by external force.

HOPE ITS HELPS!!

[tex]\boxed{\color{red}\huge\tt\bold\purple{Answer}}[/tex]

Inertia is the tendency of an object to continue in the state of rest or of uniform motion. The object resists any change in its state of motion or rest.

Explanation:

ahhh, maybe you mean , what happens when a light ray hits the interface of two media perpendicular to the normal.

if that is the case then the light ray will not bend but it will travel in the same direction in the second medium as it was travelling in it's first medium

hope this helps bro

Answer:

can you clear your question I can't understand

Answer:

its two valence electrons

Explanation:

Calcium is a group 2 element with two valence electrons. Therefore, it is very reactive and gives up electrons in chemical reactions.

UR WELCOME!! :)

Answer:

E = 25 J

Explanation:

Given that,

Spring constant, k = 200

Compression, x = 0.5

We need to find the potential energy stored in the spring. The formula for the stored potential energy in the spring is given by :

[tex]E=\dfrac{1}{2}kx^2[/tex]

Put all the values,

[tex]E=\dfrac{1}{2}\times 200\times 0.5^2\\\\E=25\ J[/tex]

So, 25 J of potential enersy is stored in the spring.

Answer:

A.

Explanation:

I think it might be the big number A

Answer:

new PE at top=original PE - energy lost

mgh=.2(9.8)20-30

Explanation:

mgh=.2(9.8)20-30 = 9.2

Answer:

1. less. 2 greater. 3. the same. 8. An FM radio station broadcasts its signal at a fre​- ... wave 3. | 3x108 = 269.15x107). = 3.20m. 2. An electromagnetic AM-band radio wave could have Base your answers to questions 9 and 10 on the informa- ... X rays. -Microwaves. -Long

Answer:

nice calculations!

Explanation:

Answer:

m=6.25kg

Explanation:

Force= mass × acceleration

50=m×8

make m subject of the formula...

m=50/8

m=6.25kg

Answer:

[tex]\boxed {\boxed {\sf 6.25 \ kilograms}}[/tex]

Explanation:

According to Newton's Second Law of Motion, force is the product of mass and acceleration.

[tex]F= m \times a[/tex]

We know the force is 50 Newtons and the acceleration is 8 meters per second squared. Let's convert the units to make the problem and unit cancellation easier.

1 Newton is equal to 1 kilogram meter per square second (1 kg*m/s²), so the force of 50 N is equal to 50 kg*m/s².

Now we know 2 values:

Substitute the values into the formula.

[tex]50 \ kg *m/s^2= m \times 8 \ m/s^2[/tex]

Since we are solving for the mass, we must isolate the variable, m. It is being multiplied by 8 meters per square second and the inverse of multiplication is division. Divide both sides by 8 m/s².

[tex]\frac {50 \ kg *m/s^2}{8 \ m/s^2}= \frac{m \times 8 \ m/s^2}{8 \ m/s^2}[/tex]

[tex]\frac {50 \ kg *m/s^2}{8 \ m/s^2}= m[/tex]

The units of meters per square second (m/s²) cancel.

[tex]\frac {50 \ kg }{8 }=m[/tex]

[tex]6.25 \ kg =m[/tex]

The mass is 6.25 kilograms.

Answer:

Thermal physics

Explanation:

Because it uses temperature

Answer:

In my opinion both are easier if you'll work hard on it...

Answer:

B

A

Explanation:

please mark as brainliest :)

Answer:

Density = 4.84 g/cm³

Explanation:

Given the following data;

Mass = 30 g

Volume = 6.2 cm³

To find the density of the piece of iron;

Density can be defined as mass all over the volume of an object.

Simply stated, density is mass per unit volume of an object.

Mathematically, density is given by the equation;

[tex]Density = \frac{mass}{volume}[/tex]

Substituting into the equation, we have;

[tex]Density = \frac{30}{6.2}[/tex]

Density = 4.84 g/cm³

Answer:

c they obey inverse square law

Answer: Create a hypothesis

Explanation:

From the information given, information has been gathered and the identification to ascertain if there's a change. Then, an hypothesis has to be created in order to know what the problem is.

One has to carry out some research in order to know what went wrong and should also validate the hypothesis by consulting with ones peers. By doing this, the most likely causes of the issues will be gotten.

Answer:

(I'm not 100% sure about this)

Maybe its because the soccer ball is faulty. Such troublemakers can include holes in the ball, preventing it from inflating.

Answer:

ml tayo 1v1 durugin kita

Explanation:

ano takot ml 1v1

Answer:

334.314 (kJ)

Explanation:

1) the formula for the required energy is: Q=c*m(Bp-t), where c - 4100 J/kg*C; m - 0.9 kg; Bp - 100.6 C; t - 10 C.

2) according to the formula above:

Q=4100*0.9*(100.6-10)=41*9*906=334314 (J).

Answer:

Explanation:

The Law of Momentum Conservation for us has the equation

[tex][m_rv_r+m_gv_g]_b=[m_rv_r+m_gv_g]_a[/tex] and filling in:

[tex][(.50)(5.0)+(.50)(0)]=[(.50)(2.0)+(.50)v_g][/tex] and

2.5 = 1.0 + .50v and

1.5 = .50v so

v = 3 m/s

The final speed of the green ball is 3m/s. This can be calculated by the law of conservation of momentum. Thus, the correct option is D.

The principle of the law of conservation of momentum states that if any two objects undergo collision, then the total momentum of the objects before and after the collision will be the same if there is no external force acting on the colliding objects.

The Law of Conservation of Momentum has the equation which is:

m₁ × u₁ + m₂ × u₂ = m₁ × v₁ + m₂ × v₂

where, m₁ = mass of object 1,

u₁ = initial velocity of object 1 before collision,

m₂ = mass of object 2,

v₁ = final velocity of object 1 after collision,

v₂ = final velocity of the object 2 after collision.

0.50 × 5 + 0.50 × 0 = 0.50 × 2 + 0.50 × v₂

2.5 + 0 = 1.0 + 0.50 × v₂

2.5 - 1.0 = 0.50 × v₂

1.5 = 0.50 × v₂

1.5/ 0.5 = v₂

v₂ = 3m/s

Therefore, the correct option is D.

Learn more about Momentum here:

https://brainly.com/question/24030570

#SPJ2

Answer:

194 degrees farenheit! hot

Explanation:

(90°C × 9/5) + 32 = 194°F

Answer:

194

Explanation:

to get from celcius to Fahrenheit

multiply temperature by 2 and add 30

Answer:

[tex] |B| = \sqrt{ {B _{x} }^{2} + {B _{y} }^{2} } \\ = \sqrt{ {7}^{2} + {5}^{2} } \\ = \sqrt{74} \\ = 8.6[/tex]

[tex]let \: the \: angle \: be \: \theta \\ \tan(\theta) = \frac{B _{y} }{B _{x} } \\ \tan( \theta) = \frac{ - 5}{7} \\ \theta = { \tan }^{ - 1} ( \frac{ - 5}{7} ) \\ = 35.5 \degree[/tex]

Answer:

The eddy currents will be very small.

Explanation:

An object made of several thin conducting layers separated by insulation may not be affected by magnetic damping because the eddy current produced in each layer due to induction will be very small and the opposing magnetic flux produced by the eddy currents will be very small.

Answer:

We can reasonably improve a machines ability to do work by reducing the friction between the moving parts of machine.

Explanation:

According to the law of conservation of energy, the energy can neither be created nor destroyed.

Answer:

Explanation:

Since this is not parabolic motion, it is one-dimensional motion. Very simple. What we are given is

mass: 15.0 kg

initial velocity: 2.0 m/s

acceleration: .75 m/s/s

time: 6.0 seconds

Since we are looking for final velocity, the equation we need for this is

v = v0 + at that says final velocity is equal to the initial velocity plus the acceleration of the object times how long it travels. We don't have a need for the mass here at all.

[tex]v=2.0\frac{m}{s}+.75\frac{m}{s^2}(6.0s)[/tex]

Notice that one of the seconds labels to the right of the plus sign cancel out, leaving us with like units...which we HAVE to have if we want to add.

Simplifying a bit gives us

v = 2.0 m/s + 4.5 m/s so

v = 6.5 m/s

Answer:

v = 10.09 m / s,   8.78 North of East

Explanation:

The easiest way to solve this exercise is to decompose the velocities into a coordinate system, where the x-axis coincides with the West-East direction and the y-axis coincides with the South-North direction.

athlete's velocity v₁ₓ = 3 m / s

wind speed 2 v₂ = 10 m / s with direction 65 north of east

          sin 65 = v_{2y} / v₂

          cos 65 = v₂ₓ / v₂

          v_{2y} = v₂ sin 65

          v₂ₓ = v₂ cos 65

          v_{2y} = 10 sin 65 = 9.06 m / s

          v₂ₓ = 10 cos 65 = 4.23 m / s

wind speed 3 v₃ = 8 m / s with direction 70 south of east

This angle measured from the positive side of the x-axis is

          θ = 360 - 70

          θ = 290

          sin 290 = v_{3y} / v₃

          cos 290 = v₃ₓ / v₃

          v_{3y} = v₃ sin 290

          v₃ₓ = v₃ cos 290

           v_{3y} = 8 sin 290 = -7.52 m / s

          v₃ₓ = 8 cos 290 = 2.74 m / s

now we can find each component of the velocity

X axis

        vₓ = v₁ + v₂ₓ + v₃ₓ

        vₓ = 3 + 4.23 + 2.74

        vₓ = 9.97 m / s

Y axis  

        v_y = v_{2y} + v_{3y}

        v_y = 9.06 - 7.52

         v_y = 1.54 m / s

to find the modulus let's use the Pythagorean theorem

         v = [tex]\sqrt{v_x^2 + v_y^2 }[/tex]

         v = [tex]\sqrt{9.97^2 + 1.54^2}[/tex]

         v = 10.09 m / s

let's use trigonometry for the direction

         tan θ = v_y / vₓ

        θ = tan⁻¹ v_y / vₓ

        θ = tan-1 1.54 / 9/97

         θ = 8.78

the address is 8.78 North of East

The kinetic energy of the rocket should be A. it doubles.

Kinetic energy represents the energy where an object or a particle should be the reason for its motion. It transfers energy than it should be done on an object by applying a net force, so the object speeds up and thereby gains kinetic energy. In the case when the speed increased to 2v so the kinetic energy should also doubles.

Learn more about speed here: https://brainly.com/question/17052831

4E

The elastic potential energy of an elastic material (e.g a spring, a wire), is the energy stored when the material is stretched or compressed. It is given by

U = [tex]\frac{1}{2}kx^2[/tex]               --------------------(i)

Where;

U = potential energy stored

k = spring constant of the material

x = elongation (extension or compression of the material).

From the first statement;

when elongation (x) is 4cm, energy stored (U) is E

Substitute these values into equation (i) as follows;

E = [tex]\frac{1}{2}k(4)^2[/tex]

E = 8k

Make k subject of the formula    

k = [tex]\frac{E}{8}[/tex]   [measured in J/cm]

From the second statement;

It is stretched by 4cm.

This means that total elongation will be 4cm + 4cm = 8cm.

The potential energy stored will be found by substituting the value of x = 8cm and k = [tex]\frac{E}{8}[/tex] into equation (i) as follows;

U = [tex]\frac{1}{2}\frac{E}{8} (8)^2[/tex]  

U = [tex]\frac{1}{2}{8E}[/tex]

U = [tex]{4E}[/tex]

Therefore, the potential energy stored will now be 4 times the original one.