A car has a kinetic energy of 103kJ.
The speed of the car is 13.1 m/s.
Calculate the mass of the car.
Give your answer to 2 significant figures.

Answer:

Explanation:

vf=0

vi = 17

a = -0.8

Δx = ?

vf^2 = vi^2 + 2 a Δx

Δx = (vf^2 - vi^2) / 2a

Δx = (0-17^2) / 2 (-0.8)

Δx = 180.625 m

Complete Question

A flywheel in a motor is spinning at 510 rpm when a power failure suddenly occurs. The flywheel has mass 40.0 kg and diameter 75.0 cm . The power is off for 40.0 s , and during this time the flywheel slows down uniformly due to friction in its axle bearings. During the time the power is off, the flywheel makes 210 complete revolutions. At what rate is the flywheel spinning when the power comes back on(in rpm)? How long after the beginning of the power failure would it have taken the flywheel to stop if the power had not come back on, and how many revolutions would the wheel have made during this time?

Answer:

[tex]\theta=274rev[/tex]

Explanation:

From the question we are told that:

Angular velocity [tex]\omega=510rpm[/tex]

Mass [tex]m=40.kg[/tex]

Diameter d [tex]75=>0.75m[/tex]

Off Time [tex]t=40.0s[/tex]

Oscillation at Power off [tex]N=210[/tex]

Generally the equation for Angular displacement is mathematically given by

 [tex]\theta_{\infty}=\frac{w+w_0}{t}t[/tex]

 [tex]w=\frac{2*\theta_{\infty}}{t}-w_0[/tex]

 [tex]w=\frac{28210}{40*(\frac{1}{60})}-510[/tex]

 [tex]w=120rpm[/tex]

Generally the equation for Time to come to rest is mathematically given by

 [tex]t=(\frac{\omega_0}{\omega_0-\omega})t[/tex]

 [tex]t=(\frac{510}{510-120rpm})(40.0)(\frac{1}{60})[/tex]

 [tex]t=0.87min[/tex]

Therefore Angular displacement is

 [tex]\theta =(\frac{120+510}{2})0.87[/tex]

 [tex]\theta=274rev[/tex]

For 1000 seconds , a current of 0.1 A flows so as to transfer charge of 100C

Answer:

Explanation:

V = I * R

V = 4 * 12.1 = 48.4 v

Answer:

B= 4 A=5

Explanation:

Answer:

I think C

Explanation:

If im right give brainliest :)

Answer:

B

A

Explanation:

please mark as brainliest :)

Explanation:

An oven thermostat regulates the temperature inside an oven. The thermostat's temperature-sensitive probe measures the oven's warmth, switching the heat on and off as necessary to maintain the correct temperature.

Answer:

Nitric acid, also known as aqua fortis and spirit of niter, is a highly corrosive mineral acid. The pure compound is colorless, but older samples tend to acquire a yellow cast due to decomposition into oxides of nitrogen and water. Most commercially available nitric acid has a concentration of 68% in water.

Explanation:

Good morning...

Nitric acid production is mainly driven by fertilizer industry. Nitric acid is used in the production of ammonium nitrate and calcium ammonium nitrate which find applications as fertilizers.

Answer:

A temporary orbit in which a spacecraft awaits the next phase of its mission .

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:

5m/sec^2

Explanation:

Distance=1200m

Time=4 min

1=60sec

4=4 x 60

=240sec

Velocity=Distance/Time

Velocity=1200/240

Velocity=5m/sec^2

Mark me as brainliest

Answer:

It is connected in series with the circuit

Explanation:

This is because to measure the current in the circuit, the current in the circuit has to flow through the ammeter. As such, the ammeter must be connected in series with the circuit so as to measure the current flowing through the circuit.

So, to measure the current flowing through a circuit with an ammeter, the ammeter must be connected in series with the circuit.

Answer:

D. Frequency

Explanation:

The energy of an  electromagnetic wave is proportional to frequency, mathematically it is expressed as;

E ∝ f

E = hf

where;

h is Planck's constant = 6.626 x 10⁻³⁴ Js

The equation above can also be expanded to;

[tex]E = hf = h \frac{c}{\lambda}[/tex]

where;

c is speed of light = 3 x 10⁸ m/s

λ is the wavelength of the electromagnetic wave

Since the speed of light is constant, we can conclude that the energy of the electromagnetic wave is directly proportional to its frequency and inversely proportional to its wavelength.

Therefore, the correct option for direct proportionality is FREQUENCY

c- temperature

The speed of sound increases with increasing temperature .

Answer:

the power output P = 1484 W

Explanation:

Power P  = Force× speed

Given that motor of a battery-powered scooter can maintain a speed of 5.3 m/s by providing a force of 280 N.

Therefore,the power output of the motor P = 280×5.3 = 1484 W

Hence, the power output P = 1484 W

Answer:

Explanation:

You didn't fill in the proper masses which is why you never got an answer to this. But that's ok...I got you. I happen to know what they are! We will use the universal law of gravitation and the gravitational constant to solve this.

[tex]F_g=\frac{Gm_1m_2}{r^2}[/tex] and filling in:

[tex]F_g=\frac{(6.67*10^{-11})(5.98*10^{24})(7.36*10^{22})}{(3.84*10^8)^2}[/tex] The denominator is the radius of the earth plus the radius of the moon plus the distance between their surfaces, just FYI.

That gives us that

[tex]F_g=1.99*10^{20}N[/tex] Not sure what your choices entail, but I'd have to say, taking into consideration that maybe your problem didn't figure in the distance between the surfaces, you'd be at choice B.

Explanation:

Optics is a branch of physics that is the study of light and vision. ... The branch of physics dealing with the nature and properties of electromagnetic energy in the light spectrum and the phenomena of vision. In the broadest sense, optics deals with infrared light, visible light, and ultraviolet light.

Answer:

it is maybe A but i'm not 100% sure

Explanation:

its the only one that is mixed

Answer:

It depends on the medium

Explanation:

2021 edge

The energy of a sound wave decreases as it travels through a medium to another medium. Thus, the correct option is D.

A sound wave is the pattern of disturbance which is caused by the energy which is travelling away from the source of the sound in that medium. Sound waves are the longitudinal waves. This means that the propagation of these vibration of particles is parallel to the energy which this wave propagation direction has. When the atoms in the medium are set in vibration then they move back and forth in a direction. This continuous to occur in back and forth motion resulting in a high-pressure and a low-pressure region in the medium and thus propagating sound.

Sound wave is the physical vibration wave which travel through the air to reach the ears of organisms. Sound energy is the result when force makes an object to vibrate. A wave can lose energy as it travels through a medium because the medium can also absorb the energy from the wave. The medium changes some of the acoustic energy of the sound wave into heat energy.

Therefore, the correct option is D.

Learn more about Sound wave here:

https://brainly.com/question/21995826

#SPJ2

Answer:

Explanation:

Force= (q1q2)/(4/\Ęr2)

3×10^6= (1.602×10^-19)^2/(r^2)

r^2=(2.27×10^-33)/(3×10^6)

r^2=8.55×10^-45

r= 9.25×10^-23

Answer:

nuclear fission

Explanation:

nuclear fission

Answer: Nuclear fission

Explanation:

Answer:

d

Explanation:

Answer:

B

Explanation:

Answer:

Equal to the frictional force

Explanation:

Question; The options given with regards to a similar question posted online are;

A. Equal (equivalent) to the frictional force

B. Larger than the frictional force

C. Equal to the object's weight

D. More than the object's weight

Explanation

According to Newton's first law of motion, every object shall remain at rest or continue moving with uniform (constant speed) motion unless there is a net force acting on the object

Given that the velocity of the massive block, lying on the surface that has friction, being pulled by the rope = Constant

Therefore;

The net force acting on the moving block while being pulled by the rope = 0

From which we have;

The pulling force = The resistive force

Where;

The pulling force = The (pulling) force (applied) on the rope

The resistive force = The frictional force of the surface which tends to prevent the motion of the block

Therefore, given that the net force acting on the block = 0

The force on the rope = The frictional force (of the surface)

The correct option is option A. Equal to the frictional force.

multiplication of two vectors yields a vector oroduy

Answer:

double Replacement

Explanation:

The mutual replacement of radical and ions between the two compounds or molecules is called double replacement.

General equation : AB+CD = AD +B

Answer:

For Ryan:

[tex]at \: highest \: point : v = 0 \\ velocity = 0 \: {ms}^{ - 1} [/tex]

For the football kicked:

[tex]s = ut - \frac{1}{2} g {t}^{2} \\ for \: range : s = 0 \\ u \sin( \theta) = \frac{gt}{2} \\ t = \frac{2u \sin(\theta) }{g} \\ range(x) = ut \\ x = \frac{ {2u {}^{2} \sin(\theta) }^{} }{g} \\ \frac{50 \times 9.8}{ {2318.9}^{} } = \sin(\theta) \\ \\but \: 0 = u \sin(25) - 2 \times 9.8 \times 50 \\ u = 2318.9 \: {ms}^{ - 1} \\ \theta = 12.2 \degree[/tex]

Answer:

the highest point for the first question is 0 meters per second

the answer for question 2 is 45 degrees

Answer: The energy incident on the solar panel during that day is [tex]9.24 \times 10^{7} J[/tex].

Explanation:

Given: Mass = 250 kg

Initial temperature = [tex]16^{o}C[/tex]

Final temperature = [tex]38^{o}C[/tex]

Specific heat capacity = 4200 [tex]J/kg^{o}C[/tex]

Formula used to calculate the energy is as follows.

[tex]q = m \times C \times (T_{2} - T_{1})[/tex]

where,

q = heat energy

m = mass of substance

C = specific heat capacity

[tex]T_{1}[/tex] = initial temperature

[tex]T_{2}[/tex] = final temperature

Substitute the values into above formula as follows.

[tex]q = 250 kg \times 4200 J/kg^{o}C \times (38 - 16)^{o}C\\= 250 kg \times 4200 J/kg^{o}C \times 22^{o}C[/tex]

As it is given that water absorbs 25% of the energy incident on the solar panel. Hence, energy incident on the solar panel can be calculated as follows.

[tex]\frac{25}{100} \times q = 250 kg \times 4200 J/kg^{o}C \times 22^{o}C\\q = 9.24 \times 10^{7} J[/tex]

Thus, we can conclude that the energy incident on the solar panel during that day is [tex]9.24 \times 10^{7} J[/tex].

Answer:

funny bone and compact bone

Explanation:

your funny bone only reacts if you hit it against something the compact bone is the heaviest and strongest bone in your body and the bone marrow is soft sponge like tissue in the center if most bones that produces white and red blood cells