C. Members of the same species work together for survival
Explanation:
It is given that,
Velocity of the electron, 
Magnetic field, 
Charge of electron, 
(a) Let
is the force on the electron due to the magnetic field. The magnetic force acting on it is given by :

![F_e=1.6\times 10^{-19}\times [(2\times 10^6i+3\times 10^6j)\times (0.030i-0.15j)]](https://tex.z-dn.net/?f=F_e%3D1.6%5Ctimes%2010%5E%7B-19%7D%5Ctimes%20%5B%282%5Ctimes%2010%5E6i%2B3%5Ctimes%2010%5E6j%29%5Ctimes%20%280.030i-0.15j%29%5D)


(b) The charge of electron, 
The force acting on the proton is same as force on electron but in opposite direction i.e (-k). Hence, this is the required solution.
The myosin heads pull on the actin, bringing them closer together
When dealing with multiple forces acting on a body, it is advisable to draw a free-body diagram like that shown in the picture. There are four forces acting on the box: weight (W) pointing straight down, normal force perpendicular to the slope denoted as Fn, force used to push the box upwards along the slope and the frictional force acting opposite to the direction of motion of the box denoted as Ff. Frictional force is equal to coefficient of kinetic friction (μk) multiplied with Fn.
∑Fy = Fn - mgcos30° = 0
Fn = (50)(9.81)(cos 16) = 471.5 N
When in motion, the net force is equal to mass times acceleration according to Newton's 2nd Law of Motion:
Fnet = F - μk*Fn - mgsin30° = ma
250 - (0.2)(471.5 N) - (50)(sin 16°) = (50)(a)
a = 2.84 m/s²
Speed can never be negative because it does not depend in which direction the car moves whereas, velocity will change if a car turns from due North to East.
Quantities which can be described only by their magnitudes are called scalars and those which are described by both, magnitude and direction are vectors