Author Question: A soccer ball is kicked with a velocity of 25 m/s at an angle of 45 above the horizontal. What is ... (Read 162 times)

imowrer · **on:** Jul 27, 2018

A soccer ball is kicked with a velocity of 25 m/s at an angle of 45 above the horizontal. What is the vertical component of its acceleration as it travels along its trajectory? (Neglect air friction.)

A) g sin(45) upward
B) g downward
C) zero
D) g cos(45) downward
E) g upward

Question 2

An explosion of genetic diversity similar to that which occurred during the Cambrian Period hasn't happened recently, most likely because

A) evolution of life on Earth is no longer occurring
B) such an explosion can occur only for simple organisms and not complex ones
C) there are no more ecological niches available to allow this to happen
D) of the widespread presence of efficient predators that make it much more difficult for entirely new organisms to appear