A machine does 1,500 joules of work in 30 seconds. What is the power of this machine?

Answer:

Therefore, when the radius of a sphere is increased by 25%, the surface area increases by approximately 56.25%.

Explanation:

The surface area of a sphere is given by the formula:   Surface Area = 4πr^2   where r is the radius of the sphere.  

To find the percentage increase in surface area when the radius is increased by 25%, we can follow these steps:  

1. Let's assume the initial radius of the sphere is r.

2. If the radius is increased by 25%, the new radius will be 1.25r (since 25% is equivalent to multiplying by 1.25).  

3. Now, we can calculate the initial surface area (A1) using the formula: A1 = 4πr^2.  4.

Similarly, we can calculate the new surface area (A2) using the formula: A2 = 4π(1.25r)^2 = 4π(1.5625r^2) = 6.25πr^2.  

5. The percentage increase in surface area can be calculated as follows:   Percentage Increase = ((A2 - A1) / A1) * 100

 6. Plugging in the values we obtained earlier,

we have:  Percentage Increase = ((6.25πr^2 - 4πr^2) / 4πr^2) * 100  = ((2.25πr^2) / 4πr^2) * 100  = 56.25%