A speed boat is moving at 6.4m/s [N25W] when it stats accelerating at 2.2 m/s^2 [S] for 4 seconds. Calculate the final velocity of the boat.
Answer: 7.3m/s [W44S]
He 12 physics help with question?
2015-08-28 1:46 am
回答 (1)
2015-08-30 6:24 pm
Have you studied unit vectors? I'd convert to standard angles and write
N25W = 115º
final V = [6.4cos115 i + (6.4sin115 - 2.2*4) j] m/s
final V = [-2.7 i - 3.0 j] m/s
This has magnitude
|V| = √(2.7² + 3.0²) m/s = 4.0 m/s
and direction
Θ = arctan(-3.0 / -2.7) = 48º and 228º
and since the resultant is clearly in quadrant III, Θ = 228º
which translates to W48S.
I don't see how to arrive at your answers with the data provided.
N25W = 115º
final V = [6.4cos115 i + (6.4sin115 - 2.2*4) j] m/s
final V = [-2.7 i - 3.0 j] m/s
This has magnitude
|V| = √(2.7² + 3.0²) m/s = 4.0 m/s
and direction
Θ = arctan(-3.0 / -2.7) = 48º and 228º
and since the resultant is clearly in quadrant III, Θ = 228º
which translates to W48S.
I don't see how to arrive at your answers with the data provided.
收錄日期: 2021-05-01 20:29:24
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