The answer is: " 208 g " .
_____________________________________________
Explanation:
__________________________________________
The formula/ equation for density is:
__________________________________________
D = m / V ; That is, "mass divided by volume" ;

Density is expressed as:
__________________________________________
   "mass per unit volume"; in which the "mass" is expressed in units of "g" ("grams") ; and the "unit volume" is expressed in units of:
"cm³ " or "mL";
_____________________________________________
{Note the exact equivalent: 1 cm³ = 1 mL }.
____________________________________________
→ The formula is: " D = m / V " ;
___________________________________________
in which:

"D" refers to the "density" (see above), which is: "8.9 g/cm³ " (given);

"m" refers to the "mass" , in units of "g" (grams), which is unknown; and we want to find this value;

"V" refers to the "volume", in units of "cm³ " ;
which is: "23.4 cm³ " (given);
_________________________________________________
We want to find the mass, "m" ; so we take the original equation/formula for the density:
_________________________________________________
D = m / V ;
_________________________________________________________
And we rearrange; to isolate "m" (mass) on ONE side of the equation; and then we plug in our known/given values;
to solve for "m" (mass); in units of "g" (grams) ;
___________________________________________________
Multiply each side of the equation by "V" ;
____________________________________________________
V * { D = m / V } ; to get:
____________________________________________________
V * D = m ;   ↔ m = V * D ;
___________________________________________________
Now, we plug in the given values for "V" (volume) and "D" (density) ; to solve for the mass, "m" ;
______________________________________________________
m = V * D ;

m = (23.4 cm³) * (8.9 g / 1 cm³) = (23.4 * 8.9) g = 208.26 g ;

→ Round to "208 g" (3 significant figures);
____________________________________
The answer is: " 208 g " .
_____________________________________________________

7 0

3 years ago

Question 1 of 28

amm1812

Answer: D. They are the coldest stars.

Explanation:

5 0

2 years ago

An airplane travels at 300 mi/h south for 2.00 h and then at 250 mi/h north for 750 miles. What is the average speed for the tri

Anettt [7]

Answer:

270 mi/h

Explanation:

Given that,

To the south,

v₁ = 300 mi/h, t₁ = 2 h

We can find distance, d₁

$d_1=v_1\times t_1\\\\d_1=300\times 2\\\\d_1=600\ \text{miles}$

To the north,

v₂ = 250 mi/h, d₂ = 750 miles

We can find time, t₂

$t_2=\dfrac{d_2}{v_2}\\\\t_2=\dfrac{750\ \text{miles}}{250\ \text{mi/h}}\\\\t_2=3\ h$

Now,

Average speed = total distance/total time

$V=\dfrac{d_1+d_2}{t_1+t_2}\\\\V=\dfrac{600+750}{2+3}\\\\V=270\ \text{mi/h}$

Hence, the average speed for the trip is 270 mi/h.

3 0

3 years ago