I read in one of my chapters that when a body is immersed in a container of water (kept on a weighing machine which reads ‘W’ at first )the apparent weight lost by the body is equal to the buoyant force, and thus the reading ‘W’ increases.
Then I came across a question like this -
A beaker containing water kept on a weighing machine weighs W. A body of weight ’w’ is dropped in it. It is floating & experiencing a buoyant force B, then the reading on machine is -
please give me the answer and explanation
the book says answer is (a)
but I think it is (c)
(Anwesha posted this questions)
The answer is A.
The total force acting downwards is W+w and the weighing scale is providing an equal reaction. the normal reaction offered by the weighing scale is what we get as the reading.
therefore the reading on the weighing scale must be W+w
The buoyant force is acting on the object dropped and is not contributing to the normal reaction offered by the weighing scale.
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A spacecraft starts from earth moving at constant speed to planet A which is 20 light-hour away from Earth.
It takes 25 hour (according to an earth observer) for a spacecraft to reach this planet. Assuming that clocks are synchronized at the beginning of the journey, compare the time elapsed in the spacecraft frame for this one-way journey with the time elapsed as measured by an earth-based clock?
Posted by Mona
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The following questions were posted by Nabeela. We are just posting the question as such so that the visitors can post the answers.
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Categories: Ask Physics, CBSE PHYSICS CLASS XI, Interesting Questions, KINEMATICS, Mechanics, Numerical Problems Tags: Business, earth, friction, gravitation, Iapetus, mass, Southeastern Louisiana University, velocity
What about the correctness about the relation,
st=u+0.5a(2t-1), both dimensionally or any other
Prakash Adhikari asked
The equation refers to the displacement in the tth second and hence it should have the dimensions of speed; since it is the displacement in one second.
Under this consideration, the equation is dimensionally and otherwise correct.