- #1

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Find the magnitude of the velocity of the rain with respect to the car.

Find the magnitude of the velocity of the rain with respect to Earth.

How can the magnitudes be different? I don't even know how to illustrate this.

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- Thread starter AdnamaLeigh
- Start date

- #1

- 42

- 0

Find the magnitude of the velocity of the rain with respect to the car.

Find the magnitude of the velocity of the rain with respect to Earth.

How can the magnitudes be different? I don't even know how to illustrate this.

- #2

BobG

Science Advisor

Homework Helper

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To get the velocity relative to the car, you have to add in the car's velocity. Keep in mind that the car is travelling perpendicular to the rain, so the easy way to get the magnitude of the two added together will be the Pythagorean theorem.

Draw a triangle. You have the horizontal component. You have the angle opposite the horizontal component. You also know the rain's velocity and the car's velocity are perpendicular, giving you a right triangle.

With a little trig, you can figure out both the hypotenuse and the vertical component. (The hypotenuse will be the velocity of the rain relative to the car).

- #3

andrevdh

Homework Helper

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- #4

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So the sped of the rain directly on the earth is around 28 km/h.

But as seen by the driver, rain do not falls verticaly but along the hytenuse of the right triangle. this hypotenuse measure √(51^2 +28^2) ≈58.3 km/h.

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