Car's shadow
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As Curtis drives from McDonalds at 5 m/sec, his daughter notes that as the distance between the car and the light increases, the shadow of the car gets longer. She knows that this is due to the changing angle made by the pole, the car and the light. She is curious about how fast this angle changes one second after starting to leave.

What is known:

  • The height of the pole is 4 m.
  • The height of the car is 1.5 m.
  • The speed of the car is 5 m/sec.

The Relationship among
the Pole, the Light and the Car



How fast does the angle that is made by the pole, the light and the car change 1 second after they start driving?



Derivative can be employed in this case.