Quiz 4 (DifCal2,IntCal1,IntCal2,DE1,DE2,AdvMath)

Water is flowing into a vertical cylindrical tank at the rate of 24 ft3/min. If the radius of the tank is 4 ft, how fast is the surface rising?

• 0.377 ft/min

• 0.477 ft/min

• 0.577 ft/min

• 0.677 ft/min

What number exceeds its square by the maximum amount?

• 1/4

• 1/3

• 1/2

• 1

• 243/2

• 585/4

• 633/4

• 9/2

• 2.3

• 3.2

• 3.12

• 2.03

• about the line x = 0

• about the line y = 0

• about the line y = -1

• about the line x = -1

A radioactive material decomposes at a rate proportional to the amount present. If one-third of the original amount disappears after 3,000 years, what is the half material’s half-life?

• 5,218.53 years

• 5,812.53 years

• 5,128.53 years

• 5,228.53 years

What is the differential equation of the family of parabolas having their vertices at the origin and their foci on the x-axis?

• 2x dx + y dy = 0

• 2x dy – y dx = 0

• 4x dy + x dx = 0

• 3x dy + 2y dx = 0