A 1.31 g samara -- the winged fruit of a maple tree -- falls toward the ground with a constant speed of 1.0 m/s (Figure 5-29).

Question

I understand that acceleration equals zero, but I don't understand how to find the upward force need to keep the fruit at 1.0 m/s. Is kinematics necessary in this question?

Answer 1

If there is no acceleration, as is the case here, there must be an upward force that balances the weight, so that the net force is zero.

I assume you know how to calculate the weight when you know the mass.

The 1 m/s speed will not make a difference in your answer. It is what is called the termimal speed.

Answer 2

.0119 N