Answer:
The answer is 0.83 seconds.
Explanation:
The formula of free fall is following:
Where g=9.8 m/s^2 and t=2 seconds, the rock takes:
19.6 meters. This is the half distance of the cliff. The whole distance is 39.2 meters. So it takes:
2.83 second to fall down completely. The rock takes the second half of the cliff in 0.83 seconds
Current would flow between them and they would receive a terrible shock.
Missing questions: "find the speed of the electron".
Solution:
the magnetic force experienced by a charged particle in a magnetic field is given by
where
q is the particle charge
v its velocity
B the magnitude of the magnetic field
the angle between the directions of v and B.
Re-arranging the formula, we find:
and by substituting the data of the problem (the charge of the electron is
), we find the velocity of the electron:
The correct answer is A. 250N
Work is a product of force and distance.
That is, work done=force×distance
Therefore substituting for the values in the question:
500J=force×2m
force= 500Nm/2m=250N
another unit for work done is Nm as force as the SI unit of force is newtons and distance in meters