Answer:
The speed (magnitude of the velocity) is 14.4 m/s
Step-by-step explanation:
Vertical Launch Upwards
It occurs when an object is launched vertically up without taking into consideration any kind of friction with the air.
If vo is the initial speed and g is the acceleration of gravity, the speed vf at any time is calculated by:
![v_f=v_o-g.t](https://img.qammunity.org/2022/formulas/physics/high-school/3gil418tgh7fc6m614kcvrbb3oaq2xuz3k.png)
A tennis ball is launched vertically up with an initial speed of vo=34 m/s. At time t=2 s, its speed is:
![v_f=34-9.8*2](https://img.qammunity.org/2022/formulas/physics/college/pqdprruv17562psqxrt44xdoku1t4y6wpi.png)
![v_f=34-19.6](https://img.qammunity.org/2022/formulas/physics/college/3na15q4ig2bpw3otlesn3cz8q1zrhdjfqe.png)
![v_f=14.4\ m/s](https://img.qammunity.org/2022/formulas/physics/college/iki57eyr2xs9vvd437d8yid6vhop619bff.png)
The speed (magnitude of the velocity) is 14.4 m/s