Ask a Doubt
Request a call back

Join NOW to get access to exclusive study material for best results

CBSE Class 9 Answered

why does a balloon which contains hydrogen rise up in the air and a balloon containing air does not?i know the answer but i would like a proper answer that would fetch me full 1 or 2 marks.
Asked by Vidur | 18 Feb, 2014, 10:07: PM
answered-by-expert Expert Answer
Hydrogen being lighter than air, the weight of air displaced by hydrogen ballon is greater than the weight of hydrogen. Therefore, the buoyant force on the the hydrogen balloon is greater than its weight and hence it rises up. But balloon containing air is heavier than air thus the buoyant force on it less than its weight and hence it does not rise.
Answered by | 20 Feb, 2014, 01:44: PM

Application Videos

Concept Videos

Multiple Choice Questions Practice Test
Answered Unanswered My Questions My Answers
CBSE 9 - Physics
Why do we feel light on our feet when standing in a swimming pool with water up to our armpits ?
Asked by mailtoparvathyprajith | 08 Feb, 2024, 12:13: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
A boy throws a steel ball straight up. Consider the motion of the ball only after it has left the boy's hand but before it touches the ground and assume that forces exerted by the air are negligible. For these conditions, the force(s) acting on the ball is (are): a. A downward force of gravity along with a steadily decreasing upward force b. A steadily decreasing upward force from the moment it leaves the boy's hand until it reaches its highest point on the way down there is a steadily increasing downward force of gravity as the object gets closer to the earth c. Constant downward force of gravity along with an upward force that steadily decreases until the ball reaches it highest point on the way down there is only a constant downward force of gravity d. Constant downward force of gravity only
Asked by harshsrivastava8896606 | 17 Apr, 2023, 01:47: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
why pressure increases with depth in fluid
Asked by sknv159357 | 05 Jan, 2023, 08:29: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
what is the weight of an object at the centre of the earth 
Asked by advscjaglan | 09 Aug, 2022, 08:22: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
what is Newton's contribution on gravitation?
Asked by munendramishra478 | 12 Jul, 2022, 08:42: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
bhai a liquid used to operate the break in a car
Asked by sumantk60559 | 10 Jun, 2022, 07:18: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
two satellites of a planet have period 32 day and 256 days if the radius of orbit of former is R, find the orbital radius of the letter
Asked by rk7213908 | 31 Mar, 2022, 12:28: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
weight of the body is zero in free fall why?
Asked by rk7213908 | 21 Feb, 2022, 04:48: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
my doubt is the value of G is 60673multiply10-11power but why we use some no in some different numericals like use of 6.6, some times 6.7 why please ans this ques now 🙏
Asked by mannatjohn920 | 15 Feb, 2022, 09:57: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
Find the force of gravitational attraction between the earth (m = 6 x 1024 kg) and 80 kg man if he is standing at sea level. The distance of man from earth's center is 6.38 x 106 m.
Asked by sudiptaroy0607 | 08 Jan, 2022, 04:59: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
My Class Videos Tests ₹ Plans Ask a Doubt
Get Latest Study Material for Academic year 24-25 Click here
×