A 2.0kg ball is resting at the top of a 20 m hill. if the ball rolls down the entire hill, how fast will it be going?

Speed of ball is 19.80 m/s .

Explanation:

We have , a 2.0 kg ball is resting at the top of a 20 m hill. if the ball rolls down the entire hill,We need to find how fast will it be going.Let's find out:

We know that,

Potential energy : This is the energy possessed by an object due to it's virtue of height and is given by , where m is mass , g is acceleration due to gravity & h is height !

Kinetic energy : This is the energy possessed by an object due to it's virtue of motion and is given by , where m is mass & v is the velocity of object !

By conservation of energy :

⇒

⇒

⇒

According to question , h=20 m i.e.

⇒

⇒

⇒

Hence , Speed of ball is 19.80 m/s .

answer: what are you talking about?

explanation:

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it