The rate of change of the volume of a snowball that is melting is proportional to the surface area of the snowball. suppose the snowball is perfectly spherical. then the volume (in centimeters cubed) of a ball of radius r centimeters is 4/3πr3. the surface area is 4πr2. set up the differential equation for how r is changing. then, suppose that at time t = 0 minutes, the radius is 10 centimeters. after 5 minutes, the radius is 8 centimeters. at what time t will the snowball be completely melted?

The time will be 25 minutes in which snowball be completely melted.

Step-by-step explanation:

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

Then the volume (in centimeters cubed) of a ball of radius r centimeters is

The surface area is

Set up the differential equation for how r is changing. Then, suppose that at time t = 0 minutes, the radius is 10 centimeters. After 5 minutes, the radius is 8 centimeters.

To find : At what time t will the snowball be completely melted?

Solution :

Using given condition,

....(1)

Substitute in (1),

Now, t=0 , r=10

So,

i.e.

After 5 minutes, t=5 , r=8

The equation form is

The snowball be completely melted means radius became zero.

The time will be 25 minutes in which snowball be completely melted.

answer: c.  

step-by-step explanation:

mixtures containing substances that get attracted to magnet can be separated using a magnet. we can separate iron from a mixture of sand and iron, as only iron attracts to the magnet.

answer:  

step-by-step explanation:

odd numbers are only divisible by 1 and itself.

even numbers are divisible by more than 1 and itself.

for example 6 is even because it is divisible by more than 1 and its self. 1 x 6= 6 ; 2 x 3= 6

and 7 is odd because only 7 x 1 equals seveb