Answer:
I think it's Experimental
Explanation:
it has atoms on it.
Answer:
7 s
Explanation:
u = Initial velocity of rock = 12.2 m/s
= Angle of throw = 
x = Displacement in x direction = 25 m
Displacement in x direction is given by

Time taken to reach the ground is 7 s.
Answer:
1) 
2) 
3) 

Explanation:
Given:
width of river, 
speed of stream with respect to the ground, 
speed of the swimmer with respect to water, 
<u>Now the resultant of the two velocities perpendicular to each other:</u>



<u>Now the angle of the resultant velocity form the vertical:</u>



- Now the distance swam by the swimmer in this direction be d.
so,



Now the distance swept downward:



2)
On swimming 37° upstream:
<u>The velocity component of stream cancelled by the swimmer:</u>



<u>Now the net effective speed of stream sweeping the swimmer:</u>



<u>The component of swimmer's velocity heading directly towards the opposite bank:</u>



<u>Now the angle of the resultant velocity of the swimmer from the normal to the stream</u>:



- Now let the distance swam in this direction be d'.



<u>Now the distance swept downstream:</u>



3)
Time taken in crossing the rive in case 1:



Time taken in crossing the rive in case 2:



We can use the ideal gas
equation which is expressed as PV = nRT. At a constant volume and number of
moles of the gas the ratio of T and P is equal to some constant. At
another set of condition, the constant is still the same. Calculations are as
follows:
T1/P1 = T2/P2
T2 = P2 x T1 / P1
T2 = 225 x 300 / 198
<span>T2 = 340.91 K</span>