1answer.
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
gtnhenbr [62]
3 years ago
15

The air in an inflated balloon (defined as the system) is warmed over a toaster and absorbs 130 J of heat. As it expands, it doe

s 79 kJ of work. What is the change in internal energy for the system? Express the energy in kilojoules to two significant figures.
Physics
1 answer:
Nadya [2.5K]3 years ago
8 0

Answer:

The change in internal energy for the system = - 78.87 KJ = - 79 KJ to 2 s.f

Explanation:

The first law of thermodynamics states that energy can neither be created nor destroyed but can only be transformed from one form to another.

It goes further to explain that change in the internal energy of a system (ΔU) is the sum of heat exchanged (Q) and the work done (W) by the system or on the system.

If work is done by the system, sign of work is ‘-’, if work is done on the system, the sign of work is ‘+’.

If heat is released by the system, the sign of q is ‘-’. And if heat is gained by the system, then the sign of q is ‘+’.

ΔU = Q + W

Q = 130 J

W = - 79 KJ = - 79000 J

ΔU = 130 - 79000 = - 78870 J = - 78.87 KJ = - 79 KJ

You might be interested in
Listen →
Sedaia [141]

Answer:

V = 20.5 m/s

Explanation:

Given,

The mass of the cart, m = 6 Kg

The initial speed of the cart, u = 4 m/s

The acceleration of the cart, a = 0.5 m/s²

The time interval of the cart, t = 30 s

The final velocity of the cart is given by the first equation of motion

                              v = u + at

                                  = 4 + (0.5 x 30)

                                = 19 m/s

Hence the final velocity of cart at 30 seconds is, v = 19 m/s

The speed of the cart at the end of  3 seconds

                                    V = 19 + (0.5 x 3)

                                       = 20.5 m/s

Hence, the final velocity of the cart at the end of this 3.0 second interval is, V = 20.5 m/s

6 0
3 years ago
A skier of mass 60 kg is pulled up a slope by a motor-driven cable. (a) How much work is required to pull him 75 m up a 30° slop
postnew [5]

Answer:

Explanation:

Given

mass of skier=60 kg

distance traveled by skier=75 m

inclination(\theta )=30^{\circ}

speed (v)=2.4 m/s

as the skier is moving up with a constant velocity therefore net force is zero

F_{net}=0

Force applied by cable=mg\sin \theta

F=60\times 9.8\times \sin (30)=294 N

work done=F\cdot x

W=294\cdot 75=22.125 J

(b)Power=F\cdot v

P=294\cdot 2.4=705.6 W\approx 0.946 hp

5 0
2 years ago
Increasing which two things would increase gravitational potential energy?
sukhopar [10]

Answer:

Mass and height

Explanation:

Gravitational potential energy is energy an object possesses because of its position in a gravitational field. The most common use of gravitational potential energy is for an object near the surface of the Earth where the gravitational acceleration can be assumed to be constant at about 9.8 m/s2.

Which is represented as;

PE_g=mgh

PE_g stands for gravitational potantial energy,

m stands for mass of object,

g is the gravitational constant and

h is the height.

Here we see that mass of object and height is directly proportional to the gravitational potential energy.

That means increasing in mass and height will result in increasing gravitational potential energy.

7 0
2 years ago
You are listening to the radio when one of your favorite songs comes on, so you turn up the volume. If you managed to increase t
andrew-mc [135]

To solve this problem we need to apply the corresponding sound intensity measured from the logarithmic scale. Since in the range of intensities that the human ear can detect without pain there are large differences in the number of figures used on a linear scale, it is usual to use a logarithmic scale. The unit most used in the logarithmic scale is the decibel yes described as

\beta_{dB} = 10log_{10} \frac{I}{I_0}

Where,

I = Acoustic intensity in linear scale

I_0 = Hearing threshold

The value in decibels is 17dB, then

17dB = 10log_{10} \frac{I}{I_0}

Using properties of logarithms we have,

\frac{17}{10} = log_{10} \frac{I}{I_0}

log_{10} \frac{I}{I_0} = 1.7

\frac{I}{I_0} = 10^{1.7}

\frac{I}{I_0} = 50.12 W/m^2

Therefore the factor that the intensity of the sound was 50.12W/m^2

5 0
3 years ago
The shifting of the observed wavelength of light due to the motion of the source toward or away from the observer is called the
alexdok [17]

Answer:

doppler effect

Explanation:

When the relative motion of two bodies results in the wavelength becoming shorter this means that the bodies are getting closer. This is known as blue shift.

When the relative motion of two bodies results in the wavelength becoming longer this means that the bodies are getting farther. This is known as red shift.

Collectively this phenomenon is known as the Doppler effect.

7 0
2 years ago
Other questions:
  • Transformers will not work on ______ electrical systems.
    12·2 answers
  • How is energy distributed in the ocean?
    9·1 answer
  • If you ignore air resistance after an initial force launches a projectile, name all forces acting on it as it moves through the
    14·1 answer
  • How much work is accomplished when a force of 300N pushes a box across the floor for a distance of 100 meters?
    13·2 answers
  • How are rainbows formed? Please explain.
    13·2 answers
  • What is the formula for speed or velocity?
    15·1 answer
  • State Pascal's principle of pressure . please help due tomorrow​
    11·1 answer
  • A student walks 4 block east, 7 blocks west, 1 blocks east then 2 blocks west in an hour. Her average speed is____ block/hour
    8·1 answer
  • The work-energy theorem states that a force acting on a particle as it moves over a ______ changes the ______ energy of the part
    11·2 answers
  • An object weighs 2.6 N in air and 2.2N when completely immersed in water. Determine the relative density of the object (2mks​
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!