A 70 Kg person is parachuting and experiencing a downward acceleration of 3m/s. The mass of the parachute is 5kg. The upward force on the open parachute by the air is take g=10m/sec^2.

a) 525N b)650 c)760 d)143

Question

A 70 Kg person is parachuting and experiencing a downward acceleration of 3m/s. The mass of the parachute is 5kg. The upward force on the open parachute by the air is take g=10m/sec^2.

a) 525N b)650 c)760 d)143

irishboy123 · Answer

F = ma
here you need F= net force; and m = 70+5 and they are both accelerating.....

anonymous · Answer

Could you elaborate the given clue to solution that would be helpful

michele_laino · Answer

on the system: person + parachute, are acting two forces:
the total weight force whose magnitude is $F=(70+5) \cdot 10=...$
and the resistance force $R$
Now, using the second law of Newton, we can write this:
$$\huge  F - R = \left( {M + m} \right)a$$
where $a=3$, and $M+m=70+5$, namely it is the mass of the system: person + parachute
Please, solve such equation for $R$

brrandyn · Answer

Brilliant, @Michele_Laino! Thoroughly explained.

michele_laino · Answer

thanks! :) @Brrandyn

anonymous · Answer

Awesome explanation! @Michele_Laino

michele_laino · Answer

thanks! :) @Robert136

anonymous · Answer

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