Answer:
Vf = 1.41 m/s
Step-by-step explanation:
The velocity of the disc just before the friend catches it, can be found out by using 3rd equation of motion, as follows:
2gh = Vf² + Vi²
where,
g = - 9.8 m/s² (negative sign for upward motion)
h = height = 5 m
Vi = Initial Velocity = 10 m/s
Vf = Final Velocity = ?
Therefore,
2(-9.8 m/s²)(5 m) = Vf² - (10 m/s)²
Vf² = 100 m²/s² - 98 m²/s²
Vf = √(2 m²/s²)
Vf = 1.41 m/s