When a body hanging from a spring balance is immersed in water it floats just below the surface of water
and shows 100 g loss in its weight
(i) What is the weight of the body in water?
(ii) What is the weight of the body in air?
(iii) What is the upthrust on the body?
(iv) What is the volume of the body?
Give reasons for your answers. Given: acceleration due to gravity at the place is 10 m s–2, volume of 1
g of water = 1 m L
" shows 100 g loss in its weight "
100 grams??? grams is mass not weight
100 * g where g = 10 m/s^2 ??????
then weight loss is 1000 Newtons?
To answer these questions, we need to understand the concept of buoyancy, which is the upward force exerted by a fluid on an object immersed in it. Buoyancy is caused by the pressure difference between the top and bottom surfaces of the object.
Let's go through each question step by step:
(i) What is the weight of the body in water?
To find the weight of the body in water, we need to subtract the loss in weight from the original weight in air. In this case, the body shows a 100 g loss in weight when immersed in water.
Weight in water = Weight in air - Loss in weight
Weight in water = Original weight - 100 g
(ii) What is the weight of the body in air?
The weight of the body in air can be calculated by considering the original weight before it was immersed in water. The original weight is the force exerted by gravity on the body.
Weight in air = Original weight
(iii) What is the upthrust on the body?
The upthrust on the body is equal to the weight of the water displaced by the body. According to Archimedes' principle, an object immersed in a fluid experiences an upthrust equal to the weight of the fluid displaced by its submerged volume. Since the body is floating just below the surface of the water, it is displacing an amount of water equal to its own weight.
Upthrust on the body = Weight of the body in water = Original weight - 100 g
(iv) What is the volume of the body?
To find the volume of the body, we can use the fact that the volume of 1 gram of water is equal to 1 mL.
Volume of the body = Loss in weight / (Density of water x g)
Since we are given that the loss in weight is 100 g, the volume can be calculated as:
Volume of the body = 100 g / (1 g/mL x 10 m/s^2)
In summary:
(i) The weight of the body in water is the original weight minus the loss in weight.
(ii) The weight of the body in air is the original weight.
(iii) The upthrust on the body is equal to the weight of the body in water.
(iv) The volume of the body can be calculated using the loss in weight and the known volume of 1 gram of water.