Question

15. The weight of a stone in air is 10N and that inside water is 7N. Answer the
following questions.
(a) Find the upthrust due to water and weight of displaced liquid.

Answer 1

Answer:

I think so. it is. 17N. not surw

Answer 2

Answer:

Bw = 3.0036905 N

Explanation:

Let's say weight of body in vac=W ( on earth )

Buoyancy force in Air = Ba

Buoyancy force in water = Bw

Buoyancy in a fluid = weight of fluid displaced

Let's say volume of body = V

Therefore, Ba = V x air density

And Bw = V x density of water

Now, W - Ba = 10………. (1)

And W - Bw = 7…………(2)

(1)-(2) =>

Bw - Ba = 3

V(997–1.225) kg/m3 = 3 N

V = .00030710792 m3

Therefore buoyancy force by water

Bw = V x 997 x 9.81 N

Bw = 3.0036905 N

Bonus

By (1), W - Ba = 10

W = V m3 x (1.225 x 9.81) N/m3 + 10 N

W = 10.0036905 N