# physics

posted by .

What, roughly, is the percent uncertainty in the volume of a spherical beach ball whose radius is r = 0.84 ± 0.04m ?

• physics -

v = (4/3) pi r^3

dv/dr = 4 pi r^2
(which is the surface area of course :)

dv = 4 pi r^2 dr
dv/v = 4 pi r^2 dr/(4/3)pir^3

dv/v = 3 dr/r
here dr = .04
and r = .84
so 100 * 3 dr/r = 12/.84 = 14.3 %

• physics -

how do u get dv/v = 3 dr/r ?

## Similar Questions

1. ### Physics

What, roughly, is the percent uncertainty in the volume of a spherical beach ball whose radius is r = 2.86 plus or minus .09 m?
2. ### physics

spherical aluminum ball of mass 1.22 kg contains an empty spherical cavity that is concentric with the ball. The ball just barely floats in water.Calculate the radius of the cavity.
3. ### physics

a child on a beach kicks a beach ball, giving it an initial velocity of 4.0m/s.It was sitting on the ground when given the kick. The ball lands on the beach 5.0 m away with a speed of 2.2 m/s just before it hits. the final landing …
4. ### physics

A child on a beach kicks a beach ball, giving it an initial velocity of 4.0 m/s. It was sitting on the ground when given the kick. The ball lands on the beach 5m away and closer to the ocean, with a speed of 1.6m/s just before it hits. …
5. ### Calculus

A tumor is assumed to be roughly spherical. If the radius R is found to be increasing at the rate of 0.5 mm/day when the radius is R=2 mm, how fast is the volume changing at this time?
6. ### uncertainty principle

an electron inside spherical metallic particle of volume 10^ -12 metre cube has a kinetic energy about 10 eV. use uncertainty relations to find relative uncertainty in electron velocity .
7. ### physics

an electron inside spherical metallic particle of volume 10^ -12 metre cube has a kinetic energy about 10 eV. use uncertainty relations to find relative uncertainty in electron velocity
8. ### Physics

What, roughly, is the percent uncertainty in the volume of a spherical beach ball whose radius is r=4.84±0.05m?
9. ### algebra

Sara goes on a slingshot ride in an amusement park. She is strapped into a spherical ball that has a radius of centimeters. What is the volume of air in the spherical ball?
10. ### physics

What is the uncertainty of a physics lab?

More Similar Questions