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:



The Hawaiian Island was formation by volcanic activity
Answer:
25.52 seconds
Explanation:
Speed of space ship = 0.92 c = v
c = Speed of light
Time observed from asteroid = Δt = 10 seconds
Time dilation

∴ Time interval be if measured by an observer on the Enterprise would be 25.52 seconds
The velocity vector will move you 200 miles east in 4 hours traveling at a constant speed is 50 mph. Below is the solution:
Given:
200 miles
4 hours
200 miles/ 4 hours = 50 mph, east
Hope it helps.