A ping pong ball of mass 0.0027 kg and radius 0.020 m is completely submerged 0.3 m in water. How fast is it moving when it emerges from the water?

The value speed  is  

Explanation:

From the question we are told that

   The mass of the ping pong ball is

    The  radius is  

     The depth of the ping pong inside the water is  

Gnerally the force with which the ball will emerge will from the water is mathematically represented as

Here B  is the Buoyant force on the ball which is mathematically represented as

Here   is the volume of the ball which is mathematically represented as

=>    

=>    

         is the density of water with value  

So  

=>    

So

=>  

=>  

Generally force is mathematically represented as

So

=>  

Generally  from kinematic equation

Here u  is the velocity of the ping pong at depth of  0.3 m and the value is zero given that at that point there was no motion

So

=>    

b. false

explanation:

suppose a rock in free fall is dropped off a cliff. after falling for 5 seconds, its speed would not be 100 m/s.