Suppose you swing a ball of mass (m) in a vertical circle on a string of length (l). as you probably know from experience, there is a minimum angular velocity you must maintain if you want the ball to complete the full circle without the string going slack at the top.1. find an expression for the minimum angular velocity using only the terms (g) and (l).2. evaluate the angular velocity in rpm for a 65 g ball tied to a 2.0-m-long string.

a)

b)N= 21.29 rpm

Explanation:

   Given that

Mass of the ball =m

Length of string = L

Lets take angular speed = ω

The centripetal force on the ball

F = m ω² L

To complete the circle ,at the top condition the force due to gravity should be equal to the centripetal force

Gravity force = mg

F= mg

m ω² L = m g

ω² L =  g

When L= 2 m  

Lets take g =10 m/s²

ω = 2.23 rad/s

To convert in rpm

N=Speed in rpm

N= 21.29 rpm

get the total number of pieces of fruit and divide it by 4 to get the average. the result is the answer to the problem. 14 total number of fruits and there are 4 members. 14 divided by 4 is equals to 3.5.

according to jean piaget, in what stage of cognitive development are children able to understand conservation task?

b. preoperational

just took it