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
Arturiano [62]
4 years ago
10

In a candy factory, the nutty chocolate bars contain 20.0 % pecans by mass. If 4.0 kg of pecans were used for candy last Tuesday

, how many pounds of nutty chocolate bars were made? Express your answer to two significant figures.
Physics
1 answer:
ladessa [460]4 years ago
5 0

Answer:

44.09 pounds

Explanation:

We got that 20 % of the mass of a nutty chocolate bar its pecans, if 4.0 kg of pecans were used, we need to find the X in the equation

0.2 * X = 4.0 \ kg

where X its the total mass of nutty chocolate bars produced. So, we can just divide by 0.2 on both sides, and we find:

X = 4.0 kg / 0.2

X = 20.0 \ kg

Of course, we need the total mass produced in pounds, and not in kilograms.  Looking at an conversion table, we can find that 1 kg its 2.20462 pounds, multiplying the value for total mass produced by the conversion factor we get:

X = 20.0 \ kg * 2.20462 \ \frac{pounds}{kg}

X = 44.0924 \ pounds

Now, we just need to round off to two significant figures. This is:

X = 44.09 \ pounds,

the total mass of nutty chocolate bars  made last Tuesday to two significant figures.

You might be interested in
xConsider the following reduction potentials: Cu2+ + 2e– Cu E° = 0.339 V Pb2+ + 2e– Pb E° = –0.130 V For a galvanic cell employi
slega [8]

Answer:

Approximately \rm 90\; kJ.

Explanation:

Cathode is where reduction takes place and anode is where oxidation takes place. The potential of a electrochemical reaction (E^{\circ}(\text{cell})) is equal to

E^{\circ}(\text{cell}) = E^{\circ}(\text{cathode}) - E^{\circ}(\text{anode}).

There are two half-reactions in this question. \rm Cu^{2+} + 2\,e^{-} \rightleftharpoons Cu and \rm Pb^{2+} + 2\,e^{-} \rightleftharpoons Pb. Either could be the cathode (while the other acts as the anode.) However, for the reaction to be spontaneous, the value of E^{\circ}(\text{cell}) should be positive.

In this case, E^{\circ}(\text{cell}) is positive only if \rm Cu^{2+} + 2\,e^{-} \rightleftharpoons Cu is the reaction takes place at the cathode. The net reaction would be

\rm Cu^{2+} + Pb \to Cu + Pb^{2+}.

Its cell potential would be equal to 0.339 - (-0.130) = \rm 0.469\; V.

The maximum amount of electrical energy possible (under standard conditions) is equal to the free energy of this reaction:

\Delta G^{\circ} = n \cdot F \cdot E^{\circ} (\text{cell}),

where

  • n is the number moles of electrons transferred for each mole of the reaction. In this case the value of n is 2 as in the half-reactions.
  • F is Faraday's Constant (approximately 96485.33212\; \rm C \cdot mol^{-1}.)

\begin{aligned}\Delta G^{\circ} &= n \cdot F \cdot E^{\circ} (\text{cell})\cr &= 2\times 96485.33212 \times (0.339 - (-0.130)) \cr &\approx 9.0 \times 10^{4} \; \rm J \cr &= 90\; \rm kJ\end{aligned}.

5 0
3 years ago
What is the formula for calculating the efficiency of a heat engine?
Anton [14]

Answer:

Efficiency = StartFraction T Subscript h Baseline minus T Subscript C Baseline over T Subscript h Baseline EndFraction times 100. Efficiency equals T Subscript c Baseline minus T Subscript h Baseline over T Subscript h Baseline all times 100.

7 0
3 years ago
Read 2 more answers
A changing magnetic field can produce an electric current. True or False?
Mamont248 [21]

The answer is True :) have a good day

5 0
3 years ago
8TH GRADE SCIENCE I NEED NOW DO NOT SKIP
yan [13]

Explanation:

1. Force=mass*acceleration

acceleration=force/mass

=100/50

=2m/s^2

2. Gravitational force for downward acceleration= mg-ma=m(g-a) , since a is less than g,

So it will be= 50(9.8-2)

=50(7.8)= 390N

7 0
3 years ago
Centripetal is a word used in science to mean
bogdanovich [222]
: the force that is necessary to keep an object moving in a curved path and that is directed inward toward the center of rotation a string on the end of which a stone is whirled about exerts centripetal<span> force on the stone — compare centrifugal force.</span>
7 0
3 years ago
Other questions:
  • The work done on a box moved 3 meters by a force of 6 newtons is  newton-meters.
    14·1 answer
  • A student is pouring equal amounts of water, maple syrup, and cooking oil into a glass beaker and looking at how the layers sett
    15·1 answer
  • When two 10-Ohm resistors are in parallel in a circuit, what is the net resistor value
    9·1 answer
  • A rock is thrown at a window that is located 18.0 m above the ground. The rock is thrown at an angle of 40.0° above horizontal.
    9·1 answer
  • Low-income and minority communities are often subject to racial discrimination at the hands of local government policies and act
    6·1 answer
  • A compound whose molecules contain one boron atom and three fluorine atoms would be named monoboron fluoride. Please select the
    7·1 answer
  • A california condor is sitting on the top branch of a redwood tree and has a GPE of 12,100 J. If the condor has a mass of 8kg, w
    14·1 answer
  • The magnitude of the Poynting vector of a planar electromagnetic wave has an average value of 0.724 W/m^2. What is the maximum v
    14·2 answers
  • Which of the following is the most dense?
    10·1 answer
  • 2. What would be the effect on your body if you did not have kidneys? Page
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!