A baseball player is riding a train. He throws a 100 mile/hour fastball in the direction of motion of the train. The train is traveling at a speed of 50 miles/hour with respect to the ground. How fast is the baseball traveling with respect to the ground?
A. Slightly less than 150 miles/hour
B. Exactly 150 miles/hour
C. Slightly more than 150 miles/hour

B.Exactly 150 miles/hour

Step-by-step explanation:

We are given that

Velocity of ball with respect to train,

Velocity of train=

We have to find the velocity of baseball travelling with respect to ground.

Velocity of ball with respect to train=Velocity of ball with respect to ground-Velocity of train

Velocity of ball with respect to ground=Velocity of ball with respect to train+Velocity of train

Substitute the values

Velocity of ball with respect to ground=100+50

Velocity of ball with respect to ground=150 miles/hour

Hence,option B is true.

B.Exactly 150 miles/hour

hello from mrbilldoesmath!

answer:

25x^2 + 90x + 84

discussion:

mn(x) = m(n(x)) = m( 5x + 9) =

(5x + 9)^2 + 3 =>

25x^2 + 90x + 9^2 + 3 =

25x^2 + 90x + 84                 (as 9^2 = 9*9 = 81)

which is the second choice

regards,  

mrb

p.s.   i'll be on vacation from friday, dec 22 to jan 2, 2019. have a great new year!