Unformatted text preview: river with respect to the ground and the velocity of the boat with respect to water are, respectively, v WG = -4 i , v BW = 12cos75º i + 12sin75º j = 3.11 i + 11.6 j The velocity of the boat with respect to the ground is v BG = v BW – v WG = -0.89 i + 11.6 j The magnitude and direction of vBG are v BG = √ ((-.89) 2 +11.6 2 ) = 11.6 m/s, θ = tan-1 (11.6/(-0.89)) = -85.6 + 180 = 94.4º 4.4 west of north Note that has a negative x component and positive y component. It is in the 2 nd quadrant. b) How long does the boat take to cross the river? To cross the river, the boat must move 150 m in the y direction. Therefore, t = Δ y/v y = 12.9 s...
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- Summer '08
- Work, Velocity, Cardinal direction, Relative direction, South Bank, Tomoyuki Nakayama