Parametric equations

Question

A baseball is pitched horizontally at 95 mph, or about 140 feet per second. How long does it take for the ball to reach the batter at home plate, which is about 60 feet from the mound? Parametric equations of motion are :

Answer 1

they ask for parametric equations and they give you the speed

this is really projectile motion (the ball is moving both in the x and y dir. due to downward acceleration)

but to answer the question you only need the quantities for the x-dimension:

v(t) = 140          

x(t) = 140t

 

from x = 140 t   we get 60 = 140 t

which leads to t = 3/7 s