Answer:
a.18.5 m/s
b.1.98 s
Explanation:
We are given that
a.Let 
be the initial velocity of the ball.
Distance,x=30 m
Height,h=1.8 m
Substitute the values
Initial velocity of the ball=18.5 m/s
b.Substitute the value then we get
t=1.98 s
Hence, the time for the ball to reach the target=1.98 s
<span>1.7 rad/s
The key thing here is conservation of angular momentum. The system as a whole will retain the same angular momentum. The initial velocity is 1.7 rad/s. As the person walks closer to the center of the spinning disk, the speed will increase. But I'm not going to bother calculating by how much. Just remember the speed will increase. And then as the person walks back out to the rim to the same distance that the person originally started, the speed will decrease. But during the entire walk, the total angular momentum remained constant. And since the initial mass distribution matches the final mass distribution, the final angular speed will match the initial angular speed.</span>
When you heat something of cool it down you don't change the substance you might change the why is looks, but it is still the same substance. For example you cool water to 0 degrees Celsius it turns into ice but it still is two parts hydrogen and one part oxygen H2O. Physical changes will change state and/or form but it will still be what it originally was on the molecular level. Hope that helped.
