Some plants disperse their seeds when the fruit splits and contracts, propelling the seeds through the air. the trajectory of these seeds can be determined with a high-speed camera. in an experiment on one type of plant, seeds are projected at 20 cm above ground level with initial speeds between 2.3 m/s and 4.6 m/s. the launch angle is measured from the horizontal, with +90∘ corresponding to an initial velocity straight up and −90∘ straight down. the experiment is designed so that the seeds move no more than 0.20 mm between photographic frames. what minimum frame rate for the high-speed camera is needed to achieve this? (a) 250 frames/s; (b) 2500 frames/s; (c) 25,000 frames/s; (d) 250,000 frames/s.

23000 frames/s

Explanation:

We know the maximum initial speed at which the seeds are dispersed is:

In addition, we know the maximum distance at which the seeds move between photographic frames is:

And we need to find the minimum frame rate of the camera with these given conditions. This can be found by finding the time for each frame and then the frame rate:

Finding the time:

This is the time for each frame

Now we need to find the frame rate, which is the frequency at which the photos are taken.

In this sense, frequency is defined as:

Finally:

Hence, the minimum frame rate is 23000 frames per second.

b. latent learning (the word "latent" itself means something that exists but isn't obvious, only under certain conditions! )

firearm identification is the process of analyzing the bullets and cartridge cases left at a crime scene to determine if they came from a particular firearm. marks on the bullets and cartridges may be common to every firearm of that type. these are called class characteristics.