Abig league hitter attacks a fast ball. the ball has a mass of 0.16 kg. it is pitched at 38 m/s. after the player hits the ball, it is now traveling 44 m/s in the opposite direction. the impact lasted 0.002 seconds. how big of a force did the ballplayer put on that ball

6560 N

Explanation:

m = 0.16 kg

initial velocity = u = 38 m/s

final velocity = v = -44 m/s (opposite direction)

Momentum: product of mass and its velocity = p = m*v

change in momentum = initial momentum - final momentum  

                                       = m*v - m*u = 0.16*(-44)-0.16*38

                                       = 0.16(-44-38) = 0.16*(-82) = 13.12 kg.m/s

impact: large force per small time

force = change of momentum per unit time

         = 13.12/ 0.002 = 6560 kg.m/s^2 = 6560 N

6/12=1/2

step-by-step explanation:

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form