<u>ANSWER:
</u>
If a ball is thrown into the air with a velocity of 34 feet per second, then velocity of the ball after 1 second is 2 feet per second
<u>SOLUTION:
</u>
Given, a ball is thrown into the air with a velocity of 34 feet per second
Initial velocity (u) = 34 feet per second
And also given a relation between displacement and time =
--- eqn 1
We need to find the velocity when t = 1 ; v = ?
We know that, v = u + at and 
where v is instantaneous velocity and u is initial velocity
a is acceleration
t is time interval
s is displacement
using the displacement and time relation eqn (1) we get
Now, when t = 1, displacement s = 34(1) – 16(1)




here, -ve sign indicates that object is in deceleration . so acceleration is -32 ft/s
now put a value in v = u + at
v = 34 + (-32)(1)
v = 34 – 32
v = 2 ft/s
Hence, velocity of the ball after 1 second is 2 ft/s