Answer:
https://www.slader.com/discussion/question/an-electron-is-accelerated-through-240-times-103-v-from-rest-and-then-enters-a-uniform-170-t-magnetic-field-what-are-a-the-maximum-and-b-the-9e425fbd/
( Here is solution)
The magnitude of the force on the charge by the influence of the magnetic field will be 6.6*10^-3 N
<h3>What is magnetic force?</h3>
Magnetic force, attraction or repulsion that arises between electrically charged particles because of their motion.The magnitude of the magnetic force acting on the charge is given by:

where
The magnitude of the charge 
The velocity of the charge 
The magnitude of the magnetic field 
The angle between the directions of v and B 
By substituting the values we will get:


Hence the magnitude of the force on the charge by the influence of the magnetic field will be 6.6*10^-3 N
To know more about Magnetic force follow
brainly.com/question/14411049
Sound waves....................................
For example science has discovered many amazing things like atoms,molecules which led to the development of nuclear reactors etc. Challenges would be like trying to prove theories like evolution for 100 of years trying to discover all the stuff we still don’t know exists all the mysteries of life. A lot of science is still theory we can’t prove some things until we have more advanced technology etc.
Well, if your question is how light affects plants,
then you would want to design an experiment that plays aruond with the amount of light a plant gets
thus the thing changing (or variable) would be amount of light