Answer:
The two forces acting on the object are weight due to gravity pulling the object towards earth, and drag resisting this motion. When the object is first released, drag is small as velocity is low, so the resultant force is down. This means the object accelerates towards earth.
Answer:
1. 18.25 m/s
2. 0 m/s
Explanation:
1.So the centripetal acceleration of the ball at this lowest point must be, taking gravity into account

The speed at this point would then be


2. Similarly, if T = mg, then the centripetal acceleration must be

As the ball has no centripetal acceleration, its speed must also be 0 as well.
Answer:
z = 93.2 m
Explanation:
We can appreciate that this expression is equivalent to the linear motion equation with constant acceleration
v² = v₀² + 2 a d
If we make a term-to-term comparison with the expression obtained, they are equivalent
u² = v² + 2 a z
From here we can clear the position
2 a z = u² –v²
z = (u² –v²) / 2 a
Let's calculate
For the speed to reduce the acceleration must be negative
z = (0 - 21.8²) / 2(- 2.55)
z = 93.2 m