Write out what you have which is:
initial velocity
final velocity
Y distance
degree
You do not have :
a
X distance
t
from what you have you can plug into your formulas to get time.
Answers:
a) 
b) 
Explanation:
a) The centripetal acceleration
of an object moving in a uniform circular motion is given by the following equation:
Where:
is the angular velocity of the ball
is the radius of the circular motion, which is equal to the length of the string
Then:
This is the centripetal acceleration of the ball
b) On the other hand, in this circular motion there is a force (centripetal force
) that is directed towards the center and is equal to the tension (
) in the string:

Where
is the mass of the ball
Hence:

This is the tension in the string
Ike is at the beach watching the waves in the ocean. Ike notices that some of the waves are short. Other waves are very tall and come up high above the water. Two waves that are different heights because They have different amplitudes.
Answer: Option (D) is correct
Explanation:
The different heights of the waves are due to their different amplitudes. The Amplitude of a particular wave depends upon the amount of energy being carried by waves. It the waves carry more energy than their amplitude will be higher.
But if energy carried by a wave is less than the wave will have a low amplitude. The Amplitude shows the distance covered from the rest position to peak position.