Question

A quarterback throws a football with an initial velocity of 30 m/s at an angle of 25 degrees.
a) How much time passes until the ball travels 35 m horizontally?
b) What is the height of the ball above the ground after 0.5 seconds? (assume that when thrown, the ball is 2 m above the ground.)

Answer 1

first split velocity into horizontal and vertical components

horizontal ---> 30cos(25)
vertical ----> 30 sin(25)

Then set up component equations:
x(t) = 30cos(25)*t
y(t) = -4.9t^2 + 30sin(25)*t +2

Answer 2

okay, 30cos(25)=27.19 and 30sin(25)=12.68
x(t)= 27.19(t)
y(t)= 12.68(t)

Answer 3

y(t)=-4.9^2 + 12.68(t) + 2

Answer 4

do i divide by t?

Answer 5

part a) set x(t) = 35 , solve for t ----->27.19t = 35

part b)
plug in 0.5 for t

Answer 6

a) 1.3 and b) 7.1