| 1. |
A farmer moves along the boundary of a square field of side 10m in 40s. What will be the magnitude of displacement of the farmer at the end of 2 minutes and 20 seconds? |
Answer»
we know that, ☘️ perimeter of square = 4 × side⪼ perimeter of square = 4 × 10 ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ ⠀⠀= 40m Time taken by farmer to cover 40m = 40s So, In 1 second the farmer covers 1meter distance. Now, Distance covered by the farmer at the end of 2 minutes and 20 seconds:- Time = 2minute 20 second Converting 2 minutes into seconds:- = 2 × 60 + 20 = 120 + 20 = 140 second As we know that, the farmer covers 1m distance in 1 sec , So, Distance covered by the farmer at the end of 2 minutes and 20 seconds is :- = 1 × 140 = 140M So, The farmer will cover 140m distance in 2 minutes and 20 seconds. Now, Number of rotation the farmer takes to cover the distance = Total Distance/perimeter = 140/40 = 3.5 If the farmer stars from A( initial POSITION) then after 3.5 rounds he was at point C. Therefore, Displacement is AC. ● By using Pythagoras theorem,
➛ AC² = 10² + 10² ➛ AC² = 100 + 100 ➛ AC² = 200 ➛ AC = √200 ➛ AC = 10√2
Hence Displacement of farmer at the end of 2 minutes and 20 seconds is 14.14m ━━━━━━━━━━━━━━━━━━━━━━━━━ |
|