I'm hoping someone could check my answers.

[Tiplerfan]

In 2.0 min., a duck travels 22m [36deg N of E] then paddles 65m [E 25deg S] determine
i) total distance, ii) average speed, iii)tatol displacement iv) average velocity.

Relevant equations: v%=d/t (for velocity and speed)

i) total distance 22m+65m=87m
ii) v%=87m/120s
v = 0.725m/s
iii) let N&E be positive NS comp. 22sin36deg=12.93, 65sin25deg= -27.47, 12.93-27.47= -14.54or 14.54
EW comp. 22cos36deg=17.79, 65cos25deg=58.91, 17.79+58.91= 76.7[E]

d^2=14.54m^2+58.91m^2
d=78m
iv) v=78m/120s
v=0.65m/s [E 79.3deg S]

Thanks for any help
Cheers!

 

[kamerling]

in iii) you write d^2=14.54m^2+58.91m^2 which should be d^2=14.54m^2+76.7m^2, but you have the correct final answer.

in iv) the direction is wrong. [E 79.3deg S] meant "79.3 degrees south of east" in the rest of the problem, so this is directed nearly south. the velocity was 76.7 meters to east and 14.54 meters south in 120 seconds.

 

[Moetasim]

Hello there, based on your calculations, it seems like you have correctly determined the total distance traveled by the duck (87m) and its average speed (0.725m/s). However, I would like to point out that the equation v%=d/t is typically used for calculating percentage change, and may not be the most accurate way to calculate velocity and speed in this scenario. Instead, you could use the equation v=d/t, where v is velocity, d is distance, and t is time. This would give you a more accurate measurement of the duck's speed.

Moving on to the total displacement and average velocity, I would recommend using vector addition to calculate these values. It seems like you have attempted to do so in your calculations, but there are a few errors. Firstly, the NS and EW components should be added together, not subtracted. This would give you a total displacement of 76.7m [E 14.54deg S]. To calculate the average velocity, you could use the same equation as before (v=d/t), but this time, the value of d would be the magnitude of the total displacement (76.7m) and t would be the total time taken (120s). This would give you an average velocity of 0.64m/s [E 14.54deg S].

I hope this helps clarify your calculations. Keep up the good work!