Physics question with plane?

Question

A plane drops a hamper of medical supplies from a height of 4610 m during a practice run over the ocean. The plane's horizontal velocity was 117 m/s at the instant the hamper was dropped.

The acceleration of gravity is 9.8 m/s^2. What is the magnitude of the overall velocity of the hamper at the instant it strikes the surface of the ocean? Answer in units of m/s.

Answer 1

Ignoring air resistance the hamper will continue to have horizontal speed of 117 m/s. It will gain vertical speed of
-9.81*t
where t is related to the height as
0=4610-.5*9.81*t^2
the vertical speed is -300 m/s

The magnitude of the velocity is
=sqrt(117^2+300^2)
322 m/s

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