Answer:
(a) θ= 43.89°
(b) 

Explanation:
Ball 1:

Ball 2:

As the collision is elastic, it means that kinetic energy and momentum are conserved. Following that, we apply the law of conservation of energy and momentum:

and

Where u is the velocity before the collision, and v are the velocities after the collision. Both previous equations can be simplified as:

and

This because the two balls have the same mass. We know that the cue ball is deflected and makes an angle of 30°. From conservation in x-direction, we get::

and

Solving we get:

From conservation in y-direction, we get:

From this, we solve this equation system and get the answers. Remember to add 30° to the angle obtained.
Answer:
C
Explanation:
Using the two formulas q =CV and C =<em>∈A/d where q = charge, C = Capacitance, V =Voltage, ∈=permittivity of dielectric, A = area of plates and d = distance between plates. </em>Increasing the plate separation decreases the Capacitance thereby decreasing the charge also.
Answer:
The Sun's gravity pulls on the planets, just as Earth's gravity pulls down anything that is not held up by some other force and keeps you and me on the ground.
Explanation: Newton realized that the reason the planets orbit the Sun is related to why objects fall to Earth when we drop them. I am so sorry if I get this wrong, I'm in 5th grade! ♥