Comparative investigation is a research method that makes comparison across different countries of the world. Limitation : data set in different countries may be defined differently. Benefit : the method is flexible.
Assuming you are looking for the acceleration a:
1.

2.

where T is the tension and a is the acceleration of the blocks. The acceleration of the two blocks and the acceleration of the pulley must be equal.
The torque on the pulley is given by:
3.

where

and

.
Combining the three equations:
Answer:
C
Explanation:
light can travel in a vacuum Anne the sped varies
Answer:
The correct answer is D.
D:The surface of the coating allows light from the room to pass through but blocks the light from the screen.
Explanation:
Glare is produced on a computer screen when light from some external source reflects on the screen.
Anti-glare coating do not absorb light to reduce glare but they actually reduce glare by encouraging the light from the room to pass through the screen so that less light is reflected. Polarized lenses absorbs light to reduce glare, not anti-glare coating.
Answer:
Increases.
Explanation:
The electric potential increases when the two positive charges of same magnitude bring close to one charge to another because there is repulsive force between them due to same charge and when the two opposite charges move away from each other, the potential energy decreases. When two opposite charges are brought closer together, electric potential energy decreases while on the other hand, when we move opposite charges apart from each other than the work done against the attractive force that leads to an increase in electric potential energy.