V. Answer the following questions. A metal block weighs 500 gf in air and 460 gf when completely immersed
water. Calculate the upthrust on the block.
Give reasons for the following:
(1) Cutting is easier with sharp tools.
(ii) Sometimes, people bleed from nose while climbing uphill rapidly.
(iii) A body weighs less inside water.
(iv) A balloon filled with hydrogen rises up only to a certain height.