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3 years ago

20-point physics question! :D

2 answers:

Alex3 years ago

8 0

Your hands get warm by a fire because chemical energy is converted into heat energy.

The wood - has chemical energy when you burn it, and then, heat waves rise to the air, which means that we went from :

Chemical energy ⇒ Heat energy

Alright, now, also think about, that energy can never be created not destroyed, so it was obviously transferred, and yet conserved.

If this doesn't make sense, please message me, or comment below. :))

Virty [35]3 years ago

6 0

I think, it must be a chemical. Because the fire is a chemical reaction. So, the chemical energy converted to heat energy.

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7) Three resistors having resistances of 4.0 Ω, 6.0 Ω, and 10.0 Ω are connected in parallel. If the combination is connected in

viva [34]

Answer:

A, 0.59A

Explanation:

The total resistance in the circuit is the resistances in parallel plus that in series.

Total resistance for those in parallel is;

1/(1/4 +1/6 +1/10) = 1/ (15+10+6 /60)

1/(31/60)= 60/31 ohms

Hence total resistance of the circuit is;

60/31 + 2 = (60+62)/31 = 122/31=3.94 ohms

To calculate the current flowing through the 10ohm resistance we need to know the voltage drop by subtracting the voltage drop in the 2ohm resistance from the total voltage drop.

Voltage drop on the 2 ohm resistance is;

Current on the 2 ohm resistor × 2 ohms

V = I ×R ; I - current

R - resistance

Current drop on the 2ohm resistance is;

Total voltage in the circuit/ total resistance in the circuit

12/3.94= 3.05A

Voltage drop on the 2 ohm resistance;

3.05 × 2 = 6.10volts

Hence voltage drop on the parallel resistance would be ;

12-6.10= 5.90V

Now voltage drop in a parallel circuit is the same hence 5.90v is dropped in each of the parallel resistance.

That said, the current drop on the 10 ohm resistor would be;

5.90/10 = 0.59A

Remember V= I× R so that I = V/R

6 0

4 years ago

A cheetah can maintain its maximum speed of 100 km/hr for 30.0 seconds. What minimum distance must a gazelle running 80.0 km/hr

german

Explanation:

Suppose the cheetah is initially positioned at x=0 (m) from the reference, and the gazelle is intially at poisiton x=d (m).

Then, at the worst case, that is when cheetah is running at the maximum case, the position of the gazelle relative to the reference must be larger than that of cheetah.

In equation form,

$0\text{ km}+\frac{100\text{ km}}{1 \text{ hr}}\cdot30\text{ s }\cdot\frac{1\text{ hr}}{3600\text{ s}}\le d \text{ km}+\frac{80\text{ km}}{1 \text{ hr}}\cdot30\text{ s }\cdot\frac{1\text{ hr}}{3600\text{ s}}$

$(100-80)\cdot \frac{30}{3600}\le d$

$d\ge \frac16\text{ km}=166.66 \text{m}$

8 0

3 years ago

Mechanical energy is the sum total of all the kinetic energy and

dolphi86 [110]

Answer:

Mechanical energy is the sum of kinetic and potential energy of a system

5 0

3 years ago

I NEED THE RIGHT ANSWER ASAP NO LINKS !!!<br> This is a Science question

Tanya [424]

Answer:

The answer is the top choice. (-1)

Explanation:

We are dealing with a negative number here, so we should start at negative five on the number line. From here we see that we are subtracting a negative number from it, which means we are really adding. (Review your rules for negative signs if this doesn't make sense.) So we add 4 to -5, and we get -1. Thus, we get the top choice.

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3 years ago

What effect does urbanization have on land

GrogVix [38]

Urbanization can cause a lot of problems for nature such as pollution, global warming, and depletion of wildlife such as plants and animals.

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3 years ago

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