Answer:
The right sphere is negatively charged, the left sphere is charged positively.
Explanation:
When a negatively charged rod is held above the top of left sphere, the rod will attract positive charges and repel negative charges. As the sphere are initially touching each other so positive charges from the both spheres will moves toward the rod. When we separate the spheres positive charges from right sphere have already moved toward the rod i.e. left sphere, creating a deficiency of positive charges in the right sphere and excessiveness of positive charges in left sphere , hence the right sphere will remain negatively charged and left sphere will remain positively charged.
Answer:
Magnitude of angular acceleration = -3.95 rad/s²
Explanation:
Angular acceleration is the ratio of linear acceleration and radius.
That is

Radius = 72 cm = 0.72 m
Linear acceleration is rate of change of velocity.

Angular acceleration

Angular acceleration = -3.95 rad/s²
Magnitude = 3.95 rad/s²
Ok so this is simple projectile motion problem.
if we have an object falling in free fall it is subject to gravity of -9.80m/s^2
so it says it takes 6 sec to fall and we know initial velocity was zero so we know that h=vt+1/2gt^2 so we get h=0+1/2*9.80*6^2 = 176.4m
so solving for final speed we get KE=PE = 1/2mv^2=mgh = 1/2v^2=gh so
v=sqrt(2*g*h) = sqrt(2*9.8*176.4m) = 58.8m/s final speed when it hits the ground
hope this helps you! Thanks!!