Question

Master Saheel while performing an experiment in his science
lab unmindfully he went through the following steps.
a) He placed a beaker partially filled with water on the
weighing machine.
b) He added a stone on the weighing machine outside the
beaker and noted down the weight.
c) He placed a stone tied with a fine thread inside the beaker
without touching the bottom of beaker and noted the weight.
d) He tied the stone with a fine thread and weighed with a
spring balance and found it is 150 gms.
e) Keeping suspended on the spring balance he immersed the
stone without touching the bottom of the beaker which was
placed on the weighing machine and noted the weight on the
weighing machine.
11.1.3
After completing the experiment he went to wash his hand. He
dipped the empty mug in the bucket with water. He tried to dip
the mug straight. He observed a force is pushing it upward.
Then he tilted it and filled it with some water. To his surprise he
found that the upward force is somewhat reduced.
i) Do you think when we go to market we should check the
weighing machine. YES/NO
ii) If yes, what is the thing we should see in the kitchen
weighing machine?
iii) What will happen to the weight of the beaker with stone
dipped as in case *c'?
It will be same
It will be more
It will be less
iv) What will happen to the weight of the stone as in case 'e'?
It will be same
It will be more
It will be less
v) Why is it difficult to push the mug in the bucket​

Answer 1

Answer:

Explanation:

It will be less

Answer 2

i) Yes, We should always check the weighing machine when we go to the market.

ii) Nowadays, Kitchen weighing machines are digital to give us the exact measurement of the substance. We should always check the zero before weighing anything to avoid error.

iii) The total weight of the system will increase.

iv) In case e, it will be more than the initial reading.

v) Surface Tension and buoyancy force acts on the surface of the mug.

Explanation:

Before moving to the explanation, let us understand some basic concepts and science behind this experiment.

Surface Tension: In simple words, it is a phenomena which has the tendency to reduce the surface area to it's minimum capacity. It is due to this tension, objects which are denser than water floats on it.

• Force of Buoyancy: It is the force exerted by the liquid (fluid) which resists the weight of an object.

• According to the setup of our experiment, A beaker is filled with water to a certain level and placed on a weighing balance.
• A stone is tied to a thin string and placed inside the beaker without touching the bottom.
• In this case, the weight of system will definitely increase.

• Let us understand this, with an example, Let us fill the beaker with pebbles. Now, put the stone in this system and measure the weight again. What do you think must have happened now? The weight increased because of the force applied by pebbles on the stone is strong thus, we see the increase in weight.
• In our case, though the forces are not strong as compared to pebbles but "Force of Buoyancy or Buoyant Force" will act on it.
• Resulting the increase of weight. Same concept is applicable in case of (e).

• In case of question v, same forces are applied. The surface area of the mug relative to the amount of water present inside the bucket is high. Therefore, the buoyancy force will be high which makes it difficult to push mug in the bucket.