Ferns spread spores instead of seeds, and some ferns eject the spores at surprisingly high speeds. one species accelerates 1.4 μg spores to a 4.5 m/s ejection speed in a time of 1.0 ms. what impulse is provided to the spores? what is the average force on a spore?

Impulse is

The average force is

Explanation:

When a mass undergoes a change in velocity , its impulse is

and if a force is acting for time , then the impulse is given by

Now the mass of the spores in kg is

we calculate the impulse from the first formula:

Now that we have impulse, we calculate the average force on the spore from the second formula:

force tends to be low and long diustance masses are high

t = 1/400 h   ⇔ 0.0025 h ⇔ 9s ⇔ 0.15 m

any of the answers are correct.