explanation of how charges and electrostatics can contribute to the spread of infections or the control of infections?

a and c

c is 100% but i am confused in a

b. lifting dumbbell weight at 20-degree angle from the body after a 45-degree angle

i don't understand. explain it clearly

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west