A boat is travelling at a speed of 20hkm in a direction that is a 210∘ rotation from east.At a certain point it encounters a current at a speed of 12hkm in a direction that is a 40∘ rotation from east.What is the boat's speed after it meets the current?Round your answer to the nearest tenth. You can round intermediate values to the nearest hundredth.hkm
Q. A boat is travelling at a speed of 20hkm in a direction that is a 210∘ rotation from east.At a certain point it encounters a current at a speed of 12hkm in a direction that is a 40∘ rotation from east.What is the boat's speed after it meets the current?Round your answer to the nearest tenth. You can round intermediate values to the nearest hundredth.hkm
Identify Vectors: Identify the vectors representing the boat's speed and the current's speed. The boat's speed vector is 20km/h in a direction 210 degrees from east, and the current's speed vector is 12km/h in a direction 40 degrees from east. We will use vector addition to find the resultant speed of the boat after it meets the current.
Break Down Components: Break down the vectors into their components.The boat's speed components:- x-component (East-West axis): 20×cos(210°)- y-component (North-South axis): 20×sin(210°)The current's speed components:- x-component (East-West axis): 12×cos(40°)- y-component (North-South axis): 12×sin(40°)
Calculate Boat's Speed: Calculate the components of the boat's speed.Boat's x-component: 20×cos(210°)=20×(−0.866)≈−17.32 km/h (West)Boat's y-component: 20×sin(210°)=20×(−0.5)=−10 km/h (South)
Calculate Current's Speed: Calculate the components of the current's speed.Current's x-component: 12×cos(40°)≈12×0.766≈9.19 km/h (East)Current's y-component: 12×sin(40°)≈12×0.643≈7.72 km/h (North)
Add Vector Components: Add the components of the boat's speed and the current's speed to find the resultant vector components.Resultant x-component: −17.32km/h (boat) + 9.19km/h (current) ≈−8.13km/h (West)Resultant y-component: −10km/h (boat) + 7.72km/h (current) ≈−2.28km/h (South)
Calculate Resultant Speed: Calculate the magnitude of the resultant vector to find the boat's resultant speed.Resultant speed = ((−8.13)2+(−2.28)2)≈(66.11+5.19)≈(71.30)≈8.44km/h
Round Resultant Speed: Round the resultant speed to the nearest tenth.Resultant speed ≈8.4 km/h
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