Answer:
D.) 1m/s
Explanation:
Assume the initial angle of the swing is 12.8 degree with respect to the vertical. We can calculate the vertical distance from this initial point to the lowest point by first calculate the vertical distance from this point the the pivot point:

where L is the pendulum length
The vertical distance from the lowest point to the pivot point
is the pendulum length 2m
this means the vertical distance from this initial point to the lowest point is simply:

As the pendulum travel (vertically) from the initial point to the bottom point, its potential energy is converted to kinetic energy:


where m is the mass of the pendulum, g = 10 m/s2 is the constant gravitational acceleration, h = 0.05 is the vertical it travels, v is the pendulum velocity at the bottom, which we are trying to solve for.
The m on both sides of the equation cancel out


so D is the correct answer
Answer:
Explanation:
Electric forces exist among stationary electric charges; both electric and magnetic forces exist among moving electric charges. ... The magnetic force between two moving charges may be described as the effect exerted upon either charge by a magnetic field created by the other.
I believe it would be choice A. but not 100% possitive