Saved Bookmarks
| 1. |
The surface area of a cube is decreasing at the rate of 15 sq. cm/sec. Find the rate length of the edge is 5 cm. |
|
Answer» SOLUTION :Let s be the surface area of a cube. Let X be the length of each side of the cube. `then s = 6x^2 rArr ds/dt = 12x dx/dt` Given that `ds/dt = 15 SQ. cm/sec. and x = 5 cm`. Then - 15 = 12 xx 5 dx/dt` `rArr dx/dt = - 15/60 = - 1/4 = -0 cdot 25 cm/sec`. therefore The edge is decreasing at the rate of 0 cdot 25 cm/sec`. |
|