In order to get your answer you must remember that if the exponent is negative move to the left and if the exponent is positive you have to move to the right.

$8.57 \times 10^{-4}$
The exponent is negative so move to the left:
$8. = .8 = .08 = .008 = .0008$
$= .000857$

Therefore your answer is ".000857."

Hope this helps!

6 0

3 years ago

The rate of change of the volume of a snowball that is melting is proportional to the surface area of the snowball. Suppose the

Alisiya [41]

Answer:

According to the passage, we have the next equation:

$\frac{dV}{dt} = \frac{4}{3}\pi*3*r^{2}*\frac{dr}{dt} = K*(4\pi*r^{2} )$

where "K" is a proportional constant

Leaving at the end with the next equation:

$\frac{dr}{dt} = K$

Integrating the equation, we have:

$r=K*t+C$

where "C" is a constant

Then, we have the 2 conditions for the problem:

1) t=0 → r=10

Replacing in the equation, we have C = 10

2) t=5 → r=8

Replacing in the equation, we have K = -0.4

Finally, the time which the snowball will be completely melted will be when r = 0. So replacing in the equation

$0=-0.4*t+10$

t = 25 minutes

6 0

3 years ago