Please solve these MCQ type of questions in regards of physics!

Please show full calculation or solution on how you figured out the answer and why it is correct!

1. A stone falls freely from a height of 20 m. When is its speed 9.8 m/s?

a) During the first second of the fall

b) At the end of the first second of the fall

c) Throughout the fall

d) After it has fallen 9.8 m

2. A boy throws a stone horizontally from the top of a high cliff. At some distance from the boy hands in a vertical direction where will be the stone one second later he throws it?

a) 5 m

b) 10 m

c) 15 m

d) The distance depends on the ejection speed

3. The body throws the slip towards the horizon. The vertical projection of that speed at the moment of ejection is 20 m/s, but the horizontal projection of the velocity is 10 m/s.

How long does it take for the body to reach its peak point? Assume that g = 10 m/s.

a) 1.0s

b) 1.4s

c) 2.0s

d) 3.0s

4. How long does it take for the mass point to move from point 1 to point 4 if the rotation period is 6s