answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
pickupchik [31]
2 years ago
6

In 1993, Ileana Salvador of Italy walked 3.0 km in under 12.0 min. Suppose that during 115 m of her walk Salvador is observed to

steadily increase her speed from 4.20 m/s to 5.00 m/s. How long does this increase in speed take?
Physics
1 answer:
dexar [7]2 years ago
6 0

Answer:

t = 25 seconds

Explanation:

Given that,

Distance, d = 115 m

Initial speed, u = 4.2 m/s

Final speed, v = 5 m/s

We need to find the time taken in increasing the speed.

We know that,

Acceleration, a=\dfrac{v-u}{t} ....(1)

The third equation of kinematics is as follows :

v^2-u^2=2ad\\\\\text{Put the value of a in above equation}\\\\v^2-u^2=2\times \dfrac{v-u}{t}\times d\\\\\because (a^2-b^2)=(a-b)(a+b)\\\\(v-u)(v+u)=\dfrac{2\times (v-u)d}{t}\\\\t=\dfrac{2d}{v+u}\\\\\text{Putting all the values}\\\\t=\dfrac{2\times 115}{4.2+5}\\\\t=25\ s

Hence, it will take 25 seconds to increase the speed.

You might be interested in
A 38 kg crate rests on a floor. A horizontal pulling force of 170 N is needed to start the crate
Mandarinka [93]

Answer:

0.456033049

Explanation:

F=\mu N where N=mg hence

F=\mu mg where m is mass of object, g is acceleration due to gravity whose value is taken as 9.81 m/s^{2}, \mu is the coefficient of static friction and F is the applied force.

Making \mu the subject we obtain

\mu=\frac {mg}{N} and substituting m for 38 Kg, g for 9.81 m/s^{2} and 170 N for  F we obtain

\mu=\frac{170} {38*9.81}=0.456033049

Therefore, the coefficient of static friction is 0.456033049

5 0
2 years ago
According to the nebular theory of solar system formation, what key difference in their early formation explains why the jovian
svp [43]

Answer:

The Jovian planets formed beyond the Frostline while the terrestrial planets formed in the Frostline in the solar nebular

Explanation:

The Jovian planets are the large planets namely Saturn, Jupiter, Uranus, and Neptune. The terrestrial planets include the Earth, Mercury, Mars, and Venus. According to the nebular theory of solar system formation, the terrestrial planets were formed from silicates and metals. They also had high boiling points which made it possible for them to be located very close to the sun.

The Jovian planets formed beyond the Frostline. This is an area that can support the planets that were made up of icy elements. The large size of the Jovian planets is as a result of the fact that the icy elements were more in number than the metal components of the terrestrial planets.

3 0
2 years ago
A hot–air balloon is moving at a speed of 10 meters/second in the +x–direction. The balloonist throws a brass ball in the +x–dir
IrinaVladis [17]
The ball has an initial speed of 10m/s. This is because it is moving with the balloon. Now the balloonist throws the ball 4m/s with respect to himself, so it means that he gives the ball a extra push of 4m/s, so the total speed is 14m/s. Since it takes 30 seconds to reach the ground, the distance travelled is 14*30=420m.
7 0
2 years ago
1. When the fission of uranium-235 is carried out, about 0.1 percent of the mass of the reactants is lost during the reaction. W
DerKrebs [107]

The correct answer to the question is that the lost mass has been converted into energy.

EXPLANATION:

From Einstein's theory, we know that energy and mass are inter convertible .

When some amount of mass is lost, same amount of energy equivalent to mass is produced.

Let us consider m is the mass lost during any reaction. Hence, the amount of energy produced will be-

                                 Energy E = mc^2                

Here, c is the velocity of light i.e c = 3\times 10^8\ m/s

As per the question, uranium-235 undergoes fission. The amount of mass defect is 0.1 %.

The mass defect is defined as the difference between mass of reactants and products. During the fission, energy is produced.

The energy produced in this reaction is nothing else than the energy equivalent to mass defect.  Approximately 199.5 Mev of energy equivalent to this mass defect is produced in this reaction.

6 0
2 years ago
Read 2 more answers
The magnetic field at the earth's surface can vary in response to solar activity. During one intense solar storm, the vertical c
Flauer [41]

Answer:

EMF = 33880 Volts

Explanation:

As per Faraday's law of Electromagnetic induction we know that

Rate of change in magnetic flux will induce EMF in the closed conducting loop

so we have

\phi = B.A

now we have

A = (110 \times 10^3)(110 \times 10^3)

A = 1.21 \times 10^{10}

now we have

\phi = B(1.21 \times 10^{10})

now the induced EMF through this loop is given as

EMF = (\frac{dB}{dt})(1.21 \times 10^{10})

EMF = (2.8 \times 10^{-6})(1.21 \times 10^{10})

EMF = 33880 Volts

5 0
2 years ago
Other questions:
  • a 1.2x10^3 kilogram car is accelerated uniformly from 10. meters per second to 20 meters per second in 5.0 seconds. what is the
    14·1 answer
  • Jason wanted to find the Volume of two rocks How could you use the tools below that is shown to find the volume of these irregul
    11·2 answers
  • Which elements do hydrogen fuel cells combine to produce electricity? hydrogen and oxygen hydrogen and carbon hydrogen, oxygen,
    6·2 answers
  • Estimate the monthly cost of using a 700-W refrigerator that runs for 10 h a day if the cost per kWh is $0.20.
    12·1 answer
  • A machine is currently set to a feed rate of 5.921 inches per minute (IPM). Te machinist changes this setting to 6.088 IPM. By h
    9·2 answers
  • Titanium metal requires a photon with a minimum energy of 6.94×10−19J to emit electrons. If titanium is irradiated with light of
    10·1 answer
  • A transformer is to be used to provide power for a computer drive. The number of turns in the primary is 1000, and it delivers a
    10·1 answer
  • A block moves at 5 m/s in the positive x direction and hits an identical block, initially at rest. A small amount of gunpowder h
    10·1 answer
  • Elias serves a volleyball at a velocity of 16 m/s. The mass of the volleyball is 0.27 kg. What is the height of the volleyball a
    14·1 answer
  • An observer O is standing on a platform of length L = 90 m on a station. A rocket train passes at a relative (constant) speed of
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!