A balloon is a sphere with a radius of 5.0 m. The force of air against the walls of the balloon is 45 N. What is the air pressure inside the balloon? (surface area = 12.56 x radius^2; 1 Pa = 1 N/m^2)

A. 1.4 x 10^3 Pa

B. 3.6 x 10^2 Pa

C. 1.4 x 10^-1 Pa

D. 3.6 x 10^-2 Pa

***Idk how to solve this... pls explain?? thx :)

Question

A balloon is a sphere with a radius of 5.0 m. The force of air against the walls of the balloon is 45 N. What is the air pressure inside the balloon? (surface area = 12.56 x radius^2; 1 Pa = 1 N/m^2)

A.       1.4 x 10^3 Pa

B.       3.6 x 10^2 Pa

C.       1.4 x 10^-1 Pa

D.       3.6 x 10^-2 Pa

***Idk how to solve this... pls explain?? thx :)

jim_thompson5910 · Answer

Do you know the surface area of a sphere?

anonymous · Answer

umm is it 4(pi)(r^2) ??? idk lol

jim_thompson5910 · Answer

good

jim_thompson5910 · Answer

so the surface area of the balloon is ???

anonymous · Answer

4(3.14)(5^2)
=4(3.14)(25)
=100(3.14)
=314
??

jim_thompson5910 · Answer

good

jim_thompson5910 · Answer

that's the surface area in square meters

anonymous · Answer

mmk :)

anonymous · Answer

what do i do next? :O

jim_thompson5910 · Answer

find the pressure in pascals

1 Pa = 1 N/m^2

jim_thompson5910 · Answer

so effectively, you're dividing the force in newtons by the surface area in m^2

anonymous · Answer

oh okay, what do i plug in tho??

anonymous · Answer

they gave me 45 N.... idk what else?? :/

jim_thompson5910 · Answer

you just found the m^2, it's 314

so

45/314 = ???

anonymous · Answer

ohhh 45/314=0.143312102

anonymous · Answer

so u turn it into 1.4 ??

jim_thompson5910 · Answer

0.14 = 1.4 x 10^-1, so it's C

jim_thompson5910 · Answer

and you were correct

anonymous · Answer

yay!! :) thank youuu :D

anonymous · Answer

answer C it is then!! :D thx :)