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
Pachacha [2.7K]
3 years ago
12

A hot iron ball of mass 200 g is cooled to a temperature of 22°C. 6.9 kJ of heat is lost to the surroundings during the process.

What was the initial temperature of the ball? (ciron = 0.444 J/g°C)
A)
23°C
B)
78°C
C)
100°C
D)
155°C
Physics
2 answers:
qaws [65]3 years ago
5 0
Heat lost or gained, H = mc(θ₂ - θ₁) 
Where m = mass, c = Specific heat capacity, θ₂= final temperature, θ₁ = initial temperature

m = 200g, c = 0.444 J/g°C, θ₁ = 22 °C  (Since it was cooled).

H = 6.9 kj = 6.9 *1000J = 6900 J

6900 = 200*0.444* (θ₂ - 22)

6900/(200*0.444)  =  θ₂ - 22

77.70 = θ₂ - 22

θ₂ - 22 = 77.7

θ₂      =  77.7 + 22 = 99.7

So initial temperature before cooling ≈ 100°C .  Option C.


vodomira [7]3 years ago
4 0

Answer:

The answer is C) 100°C

Explanation:

It's on USATestprep.

You might be interested in
Two long, straight wires are separated by a distance of 9.15 cm . One wire carries a current of 2.79 A , the other carries a cur
Dafna1 [17]

Answer:

The force is the same

Explanation:

The force per meter exerted between two wires carrying a current is given by the formula

\frac{F}{L}=\frac{\mu_0 I_1 I_2}{2\pi r}

where

\mu_0 is the vacuum permeability

I_1 is the current in the 1st wire

I_2 is the current in the 2nd wire

r is the separation between the wires

In this problem

I_1=2.79 A\\I_2=4.36 A\\r = 9.15 cm = 0.0915 m

Substituting, we find the force per unit length on the two wires:

\frac{F}{L}=\frac{(4\pi \cdot 10^{-7})(2.79)(4.36)}{2\pi (0.0915)}=2.66\cdot 10^{-5}N

However, the formula is the same for the two wires: this means that the force per meter exerted on the two wires is the same.

The same conclusion comes out  from Newton's third law of motion, which states that when an object A exerts a force on an object B, then object B exerts an equal and opposite force on object A (action-reaction). If we apply the law to this situation, we see that the force exerted by wire 1 on wire 2 is the same as the force exerted by wire 2 on wire 1 (however the direction is opposite).

3 0
3 years ago
A hiker travels south along a straight line path for 1.5 hours with an average velocity of 0.75 km/hr, then travels south for 2.
ANTONII [103]
Distance travelled in south direction= 1.5hr*0.75km/hr= 1.125km
Distance travlled in north direction= 0.90*2.5=2.25
Net displacement = 2.25-1.125= 1.125 to the north
7 0
3 years ago
Why does a gymnast rub powder on his hands before exercising on a set of parallel bars? (I need a scientific answer)
dlinn [17]

<u>Answer</u>

To increase friction for a better grip.

<u>Answer</u>

Most human beings do sweat hands especially on the palm. When this happens the person will not have a good grip of heavy objects because they will slide/slip from the hand.

<em>By applying the powder, you are trying to make the hand dry hence increasing the friction for a better grip. </em>

If the gymnast doesn't do this the parallel bars may slip from the hands and injure himself or herself.

4 0
3 years ago
Read 2 more answers
Hii Happy New year can you all please answer this​
mel-nik [20]

Answer:

truuuuuuuuuuuuueeeeeeeee

4 0
2 years ago
: Do you attract the Earth or the Earth attracts you which one is attracting with a larger force?
seraphim [82]

Answer: The Earth and you are attracted to the centers of each other by a pair of equal gravitational forces. The size of the force attracting you toward the center of the Earth is your "weight" on Earth. The size of the force attracting the Earth toward the center of you is the Earth's "weight" on you.

Explanation:

8 0
3 years ago
Read 2 more answers
Other questions:
  • You should always wear your seat belt just in case the car comes to an abrupt stop. The seat belt will hold you in place so that
    11·2 answers
  • _____ can alter wind flow and create a rain shadow effect. Beaches Lakes Mountains Oceans
    12·2 answers
  • A 0.45-m metal rod moves 0.11 m in a direction that is perpendicular to a 0.80-T magnetic field in an elapsed time of 0.036 s. A
    5·2 answers
  • 3. Using the F, m, a triangle, calculate the boy's mass. Use the "force
    8·1 answer
  • Name the 2 types of tissue that form your skin?
    5·1 answer
  • Un objeto, que se encuentra a nivel del suelo, es lanzado verticalmente hacia arriba con una velocidad de 160 km/hr. ¿Qué altura
    15·1 answer
  • What is a delta?<br><br><br><br><br><br><br><br><br><br> 20 characters...
    14·1 answer
  • Two tougboats are toeing a ship each exerts a force of 6000N and the angle between the two ropes is 60 calculate the resultant f
    7·1 answer
  • What is the likely identity of a metal if a sample has a mass of 63.5 g when measured in air and an apparent mass of 60.2 g when
    10·1 answer
  • Is light a particle or a wave? Is metal a good heat shield? Is the reason that nothing can go faster than light because we have
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!