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
kow [346]
3 years ago
11

A system experiences a change in internal energy of 36 kJ in a process that involves a transfer of 14 kJ of heat into the surrou

ndings. Simultaneously, which of the following is true?
a. Q= 14 u=36
b. U=Q-W
c. 14-36=22
d. 22 kJ of work is done on the system.
Physics
1 answer:
Andre45 [30]3 years ago
7 0

Answer:

b. U = Q - W

Explanation:

Given;

change in internal energy, ΔU = 36 kJ

heat transferred to the surroundings Q  = 14 kJ

Apply first law of thermodynamic; the change in internal energy is equal to heat added to the system minus work done by the system.

ΔU = Q - W

Since heat was lost to surroundings, Q = - Q

ΔU = (-Q) - W

36 kJ = -14 kJ - W

36 kJ + 14 kJ = - W

50 kJ = - W

W = - 50 kJ (the negative sign shows that work has been done on the system)

Thus, 50 kJ of work is done on the system.

The only correct answer in the given options is "b" U = Q-W

You might be interested in
A 970-kg sports car collides into the rear end of a 2300-kg SUV stopped at a red light. The bumpers lock, the brakes are locked,
vlabodo [156]

Answer:

22.73 m/s or 81.72 kph

Explanation

We can find the combined mass of both cars as

970 kg + 2300 kg = 3270 kg.

Then the normal force of the cars can be calculated as

F(n)= mg

Where g is acceleration due to gravity 9.8m/s^2

3270 kg ×9.8 = 32046 kg*m/s^2.

coefficient of kinetic friction between tires and road to be 0.80 × F(n)

Then the frictional force can be calculated as

= (32046kg*m/s^2 × 0.80 )

= 25636.8 kg*m/s^2

We can now calculate the work done that was used stopping the cars as

Frictional force × distance

(25636.8 kg*m/s^2 ) × 2.9m= 74346.72kg*m^2/s^2

From kinetic energy formula, the combined velocity of the car can be determined

E=0.5 M V²

√(2E/M) = V

√(2*74346.72kg*m^2/s^2 / 3270 kg) = V

V= √ (45.472)

V=6.743293m/s

the momentum of both cars can be determined as

6.743293m/s * 3270 kg

= 22050.57kg*m/s

Now the final momentum of both cars must be equal to the the momentum of

the sports car just prior to the collision. Therefore, the speed of the sports car at impact.

=(22050.57 kg*m/s) / 970 kg = 22.73 m/s

We can convert that to km/h.

22.73 m/s * 3600 s/h / 1000 m/km = 81.72 kph

7 0
3 years ago
Boston Red Sox pitcher Roger Clemens could routinely throw a fastball at a horizontal
azamat

Answer: 0.145 seconds

Explanation:

Given that Roger Clemens could routinely throw a fastball at a horizontal speed of 119.7 m/s. How long did the ball take to reach home plate 17.3 m away

Since the speed is horizontal

Using the formula for speed which is

Speed = distance/time

Where

Speed = 119.7 m/s

Distance covered = 17.3 m

Time is what we are looking for

Substitute all the parameters into the formula

119.7 = 17.3/ time

Make time the subject of formula

Time = 17.3 / 119.7

Time = 0.145 seconds.

Therefore, it will take 0.145 seconds to reach the home plates

6 0
3 years ago
Need help before 10pm tomorrow night
konstantin123 [22]
The first one is A and the second one would be C
5 0
3 years ago
Consider the following four objects: a hoop, a solid sphere, a flat disk, a hollow sphere. Each of the objects has mass M and ra
Svetlanka [38]

Answer:

Hoop.

Explanation:

The angular acceleration performed at a given torque:

\alpha = \frac{\tau}{I}

The moments of inertia of each element are described below:

Hoop

I = M\cdot R^{2}

Solid sphere

I = \frac{2}{5}\cdot M \cdot R^{2}

Flat disk

I = \frac{1}{2}\cdot M \cdot R^{2}

Hollow sphere

I = \frac{2}{3}\cdot M \cdot R^{2}

The greater the moment of inertia, the greater the torque to obtain the same angular acceleration. Therefore, the hoop requires the largest torque to receive the same angular acceleration.

8 0
3 years ago
What is the highest degrees above the horizon the moon ever gets during the year in the Yakima Valley ?
Ivahew [28]

The trickiest part of this problem was making sure where the Yakima Valley is.
OK so it's generally around the city of the same name in Washington State.

Just for a place to work with, I picked the Yakima Valley Junior College, at the
corner of W Nob Hill Blvd and S16th Ave in Yakima.  The latitude in the middle
of that intersection is 46.585° North.  <u>That's</u> the number we need.

Here's how I would do it:

-- The altitude of the due-south point on the celestial equator is always
(90° - latitude), no matter what the date or time of day.

-- The highest above the celestial equator that the ecliptic ever gets
is about 23.5°. 

-- The mean inclination of the moon's orbit to the ecliptic is 5.14°, so
that's the highest above the ecliptic that the moon can ever appear
in the sky.

This sets the limit of the highest in the sky that the moon can ever appear.

90° - 46.585° + 23.5° + 5.14° = 72.1° above the horizon .

That doesn't happen regularly.  It would depend on everything coming
together at the same time ... the moon happens to be at the point in its
orbit that's 5.14° above ==> (the point on the ecliptic that's 23.5° above
the celestial equator).

Depending on the time of year, that can be any time of the day or night.

The most striking combination is at midnight, within a day or two of the
Winter solstice, when the moon happens to be full.

In general, the Full Moon closest to the Winter solstice is going to be
the moon highest in the sky.  Then it's going to be somewhere near
67° above the horizon at midnight.


5 0
3 years ago
Other questions:
  • What kind of motion is the motion of the “flying bully”? How much and what is
    11·1 answer
  • Please help me with this question
    11·1 answer
  • If the number of homes with a pet dog is equal to 250, how many total homes are represented by the chart?
    6·1 answer
  • What does the term “retroperitoneal” mean in the terms of the location of the kidneys ?
    14·1 answer
  • A 0.0400-g positive charged ball with charge q = 6.40 μC is resting on a flat, frictionless horizontal surface. For a time of t
    15·1 answer
  • For this problem, you will only be concerned with the geometric aspects of thin-film interference, so ignore phase shifts caused
    13·1 answer
  • A car of mass 1270 kg makes a 15.0 m radius turn at 11.8 m/s on flat ground. How much centripetal force acts on it?
    13·1 answer
  • PLEASE HELP MEE I REALLY NEED IT
    15·1 answer
  • A centrifuge in a medical laboratory rotates at an angular speed of 3,400 rev/min. When switched off, it rotates through 52.0 re
    8·1 answer
  • Two resistors are connected in parallel two equivalent resistance is 3,75 ohm if one resistor has a resistance of 10ohm what is
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!