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A hovercraft is initially moving at 4 m/s northwest. It then accelerates 10 m/s² to the east for three seconds.

a. What are the components of its initial velocity?
b. What are the components of its acceleration?
c. What are the components of its final velocity?
d. What are the magnitude and direction of its final velocity?

1 Answer

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Final answer:

The hovercraft's initial velocity components are -2.828 m/s to the west and 2.828 m/s to the north. The acceleration components are 10 m/s² to the east and 0 m/s² to the north. The final velocity is 27.3 m/s at an angle of 5.9° north of east.

Step-by-step explanation:

The student question involves a hovercraft with initial and final velocities and acceleration. Let's address each part separately:

a. Initial Velocity Components

The hovercraft has an initial velocity of 4 m/s northwest. To find the components, we need to split this vector into its x (west to east) and y (south to north) components. Northwest implies a 45-degree angle to both the horizontal and vertical axes, thus:

Vx_initial = V_initial * cos(45°) = 4 m/s * cos(45°) = 4 m/s * (\(√{2}/2\)) ≈ -2.828 m/s (negative due to westward direction)

Vy_initial = V_initial * sin(45°) = 4 m/s * sin(45°) = 4 m/s * (\(√{2}/2\)) ≈ 2.828 m/s (positive due to northward direction)

b. Acceleration Components

The hovercraft accelerates to the east with an acceleration of 10 m/s². Since the acceleration is purely horizontal (eastward), the components are:

Ax = 10 m/s²

Ay = 0 m/s²

c. Final Velocity Components

The final velocity components can be calculated using the formula V_final = V_initial + a*t:

Vx_final = Vx_initial + Ax*t = -2.828 m/s + 10 m/s² * 3 s = 27.172 m/s

Vy_final = Vy_initial + Ay*t = 2.828 m/s + 0 m/s² * 3 s = 2.828 m/s

d. Magnitude and Direction of Final Velocity

The magnitude of the final velocity can be calculated using the Pythagorean theorem:

|V_final| = \(√{(Vx_final)^2 + (Vy_final)^2)}\) = \(√{(27.172 m/s)^2 + (2.828 m/s)^2)}\) ≈ 27.3 m/s

To find the direction, we use arctan(Vy_final/Vx_final):

θ = arctan(2.828/27.172) ≈ arctan(0.104) ≈ 5.9° north of east.

User Greg Enslow
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