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4 years ago

Cosmologists hypothesize and form theories to explain areas of the universe that are currently

Physics

1 answer:

topjm [15]4 years ago

6 0

Answer:

True

Explanation:

However I do Believe that with the technological advancements we have made we could explore unexplored areas

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the gasoline in a car does 40000 j of work on a car and generates a constant force of 20 n. how far did the car go?

NikAS [45]

   Work = (force) x (distance)

   40,000 J = (20 N) x (distance)

   Distance = (40,000 J) / (20 N)

=    2,000 meters

= 2 kilometers.

(20 N is not a huge force when it's being used to move a car.
It's only about 4.5 pounds.)

8 0

3 years ago

Find the momentum of a 25 kg object traveling at a speed of 4 m/s

White raven [17]

Answer:

100 kg*m/s

Explanation:

P = m*v

= 25*4 = 100

4 0

3 years ago

Please help!!A camera lens 13.3 cm from a

kumpel [21]

Answer:

f=1.92 cm

If ans is correct reply for explanation.

7 0

3 years ago

72) What is the freezing point (°C) of a solution prepared by dissolving 11.3 g of Ca(NO3)2 (formula weight = 164 g/mol) in 115

Rina8888 [55]

<u>Answer:</u> The freezing point of solution is -3.34°C

<u>Explanation:</u>

Vant hoff factor for ionic solute is the number of ions that are present in a solution. The equation for the ionization of calcium nitrate follows:

$Ca(NO_3)_2(aq.)\rightarrow Ca^{2+}(aq.)+2NO_3^-(aq.)$

The total number of ions present in the solution are 3.

To calculate the molality of solution, we use the equation:

$Molality=\frac{m_{solute}\times 1000}{M_{solute}\times W_{solvent}\text{ in grams}}$

Where,

$m_{solute}$ = Given mass of solute $(Ca(NO_3)_2)$ = 11.3 g

$M_{solute}$ = Molar mass of solute $(Ca(NO_3)_2)$ = 164 g/mol

$W_{solvent}$ = Mass of solvent (water) = 115 g

Putting values in above equation, we get:

$\text{Molality of }Ca(NO_3)_2=\frac{11.3\times 1000}{164\times 115}\\\\\text{Molality of }Ca(NO_3)_2=0.599m$

To calculate the depression in freezing point, we use the equation:

$\Delta T=iK_fm$

where,

i = Vant hoff factor = 3

$K_f$ = molal freezing point depression constant = 1.86°C/m.g

m = molality of solution = 0.599 m

Putting values in above equation, we get:

$\Delta T=3\times 1.86^oC/m.g\times 0.599m\\\\\Delta T=3.34^oC$

Depression in freezing point is defined as the difference in the freezing point of water and freezing point of solution.

$\Delta T=\text{freezing point of water}-\text{freezing point of solution}$

$\Delta T$ = 3.34 °C

Freezing point of water = 0°C

Freezing point of solution = ?

Putting values in above equation, we get:

$3.34^oC=0^oC-\text{Freezing point of solution}\\\\\text{Freezing point of solution}=-3.34^oC$

Hence, the freezing point of solution is -3.34°C

4 0

4 years ago

An air conditioner is a refrigerator with the inside of the house acting as the cold reservoir and the outside atmosphere acting

Monica [59]

Answer:

1.89*10^8 J

Explanation:

The coefficient of performance of this device is $\frac{Q}{W}$ where Q .is the useful heat supplied or removed by the considered system and W is the work required by the considered system.

Step 1

Coeffiecient of perfromance for cooling (COPC) = 1.75 = $\frac{Q}{W}$ .

Q = 1.75W

Step 2

We convert day into seconds:

1 day = 24 hrs = 86400 seconds

Step 3

Heat that can be extracted from the house in a day is:

Q = 1.75 * 1.25 * 10^3 * 86400 = 189000000 = 1.89*10^8 J

8 0

4 years ago