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
Anon25 [30]
3 years ago
12

A crane raises a crate with a mass of 75 kg to a height of 10 m. Given that the

Physics
1 answer:
Crazy boy [7]3 years ago
7 0

Answer: C. 7,350 J

Explanation:

Just did it in Apex

You might be interested in
The interior space of large box is kept at 30 C. The walls of the box are 3 m high and have a ‘sandwich’ construction consisting
White raven [17]

Answer:

\frac{\dot Q}{A} =20.129\ W.m^{-2}

T_1=27.58\ ^{\circ}C & T_2=2.41875\ ^{\circ}C

Explanation:

Given:

  • interior temperature of box, T_i=30^{\circ}C
  • height of the walls of box, h=3\ m
  • thickness of each layer of bi-layered plywood, x_p=1.25\ cm=0.0125\ m
  • thermal conductivity of plywood, k_p=0.104\ W.m^{-1}.K^{-1}
  • thickness of sandwiched Styrofoam, x_s=5\ cm=0.05\ m
  • thermal conductivity of Styrofoam, k_s=0.04\ W.m^{-1}.K^{-1}
  • exterior temperature, T_o=0^{\circ}C

<u>From the Fourier's law of conduction:</u>

\dot Q=\frac{dT}{(\frac{x}{kA}) }

\dot Q=\frac{dT}{R_{th} } ....................................(1)

<u>Now calculating the equivalent thermal resistance for conductivity using electrical analogy:</u>

R_{th}=R_p+R_s+R_p

R_{th}=\frac{x_p}{k_p.A}+\frac{x_s}{k_s.A}+\frac{x_p}{k_p.A}

R_{th}=\frac{1}{A} (\frac{x_p}{k_p}+\frac{x_s}{k_s}+\frac{x_p}{k_p})

R_{th}=\frac{1}{A} (\frac{0.0125}{0.104}+\frac{0.05}{0.04}+\frac{0.0125}{0.104})

R_{th}=\frac{1.4904}{A} .....................(2)

Putting the value from (2) into (1):

\dot Q=\frac{30-0}{\frac{1.4904}{A} }

\dot Q=\frac{30\ A}{1.4904}

\frac{\dot Q}{A} =20.129\ W.m^{-2} is the heat per unit area of the wall.

The heat flux remains constant because the area is constant.

<u>For plywood-Styrofoam interface from inside:</u>

\frac{\dot Q}{A} =k_p.\frac{T_i-T_1}{x_p}

20.129=0.104\times \frac{30-T_1}{0.0125}

T_1=27.58\ ^{\circ}C

&<u>For Styrofoam-plywood interface from inside:</u>

\frac{\dot Q}{A} =k_s.\frac{T_1-T_2}{x_s}

20.129=0.04\times \frac{27.58-T_2}{0.05}

T_2=2.41875\ ^{\circ}C

4 0
3 years ago
What are the five advantages of using machine and tools in our daily life?​
daser333 [38]

Answer:

it makes our work easy and

time saving

it multiply our force applied

it complete our work with high efficiency

by using this,less effort is required for the work.

7 0
2 years ago
A soft, silvery-white metal combines with a yellow gas to form a white crystal-like solid. What can be said about this change? T
Mandarinka [93]

Answer: it is D 2022 edge

Explanation:

5 0
2 years ago
Read 2 more answers
The rectangular coordinates of a point are (5.00, y) and the polar coordinates of
Otrada [13]

Answer:

Explanation:

Polar coordinates formula

Summary. To convert from Polar Coordinates (r,θ) to Cartesian Coordinates (x,y) : x = r × cos( θ ) y = r × sin( θ )

6 0
3 years ago
PLEASE HELP!!!!! (20 points!)
valentina_108 [34]
Step 2
step 5
step 4
step 6
step 1
step 3

thank me later
3 0
3 years ago
Read 2 more answers
Other questions:
  • A boy does 465 J of work pulling an empty wagon along level ground with a force of 111 N [31o below the horizontal]. A frictiona
    13·1 answer
  • What is the biggest star in our universe?
    8·1 answer
  • Is speed or velocity more helpful to a pilot?
    13·2 answers
  • When a bow is stretched back and an arrow is shot what type of energy conversion has occured
    12·1 answer
  • Ball A (mass of 0.5 kg) going +2.0 m/s collides with a stationary ball B (mass of 0.4 kg).
    5·1 answer
  • The μ-receptor (mu) a. plays a role in analgesia and the rewarding effects of morphine. b. overlaps with the κ-receptor in its d
    11·1 answer
  • Two charges of magnitude ‒Q and +4Q are located as in the figure below. At which position (A, B,
    15·1 answer
  • Three children are riding on the edge of a merry-go-round that is a solid disk with a mass of 102 kg and a radius of 1.53 m. The
    13·1 answer
  • MGS and later orbiters found spectral evidence for what minerals on the Martian surface? Check all that apply.
    9·1 answer
  • How fast should a girl of 35 kg run so that her kinetic energy becomes 700J<br> of?
    8·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!