Answer:
Sunscreen is like a shield, you would want a better shield to protect you than a weak one so companies try to make their sunscreen better than the rest.
This is due to the tilt of the earth on its axis. Although the Sun shines on Earth, because of how the Earth is tilted, the equator is more directly hit compared to places found on the poles. The poles are hit at an angle, therefore the sunlight they receive is lesser than the places at the equator.
Answer:
B - Person A's chair rolls backwards.
Explanation:
This can be seen simply through the Conservation of Momentum. When the ball is thrown to be, the ball's momentum(+m) is transfererd to B, so B's chair moves forward(think about it - it makes sense, doesn't it?), meaning A's chair moves backwards.
So, B.
EXTRA TIP: Try drawing a diagram to help you!