Aball rolls off a horizontal shelf a height h above the floor and takes 0.5s to hit. for the ball to take 1.0s to reach the floor the shelf's height above the floor would have to a) 2h b)3h c) sqrt(2) h d)4h

For the ball to take 1.0 s to reach the floor the shelf's height above the floor would have to be 4 h.

Explanation:

According to second equation of motion, the height or the distance covered by an object is given by :

Since, the ball rolls so the initial vertical component of velocity will be equal to 0. From above equation it is clear that,

Let h be the height above the floor when the ball taken 0.5 s to hit. At 1 s the ball is H height above the floor.

So,

After solving, H = 4 h

Hence, for the ball to take 1.0 s to reach the floor the shelf's height above the floor would have to be 4 h.

there are no correct statementd on the list of choices you provided.

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