When a 90N rock is suspended beneath the surface of water its apparent weight is 60N. what volume of water must, therefore, be displaced?
your answer must be in numbers.
Your answer must be In liters.

3.06 L

Explanation:

The apparent weight of an object floating on a liquid is given by

where

W is the real weight of the object

B is the buoyant force, which is the upward force exerted by the fluid on the object, and its magnitude is equal to the weight of the volume of fluid displaced by the object

In this case:

W = 90 N is the real weight of the rock

W' = 60 N is the apparent weight

So the buoyant force is

The buoyant force can be written as

where

is the density of the fluid

V is the volume of displaced fluid

is the acceleration due to gravity

In this case,

is the density of water

So, the volume of water displaced is:

answer: the correct answer is 1.

explanation: there are various process in which a radioactive nuclei decays:

1) alpha decay: in this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. the mass number is reduced by 4 units.

2) electron capture: in this decay process, a parent nuclei absorbs an electron and gets converted into a neutron. simply, a proton and an electron combines together to form a neutron. mass number does not change in this process.

3) gamma ray emission: it is a decay process in which an unstable nuclei gives excess energy by a spontaneous electromagnetic process. this decay releases . this process does not change the mass number.

4) positron emission: it is a type of decay process, in which a proton gets converted to neutron and an electron neutrino. this is also known as -decay. in this the mass number remains same.

from the above information, we see that only alpha-decay is producing a change in the mass number of the nucleus.