acceleration of car and throwing speed. 2 questions?

Question

1)What is the acceleration of a car that goes from rest to 71 mi/hr in 12.0 seconds?

2) At Cedar Point, you can win a prize if you predict your throwing speed. Tony decides to get an advantage and measure his throwing speed beforehand. He throws a baseball straight up as hard as he can and it comes back down to him 6.5 seconds later. At what velocity did he throw it upward?



Please solve and explan how you solved.
Thank you

Answer 1

1) Velocity is related to acceleration as
v=a*t
convert mph to feet per second as
1 mph = 1.46666667 feet per second
71*1.47/12=a in ft/s^2

2) The time to apogee is 1/2 the total flight time and
v(t)=v0-g*t
at apogee v(t)=0

so
v0=g*t
v0=32*6.5/2 ft/sec

j

Answer 2

1. a=(Vf-Vi)/t
so 71-0 divided my 23 so 5.92 mi/hr per second

2. i have no frickin idea