Question

A 17-g ball bearing rolls off an 85 cm high tabletop at 1.35 m/s. Ignoring drag, how far does the ball bearing travel horizontally before it hits the floor?

Answer 1

In the tabletop it has a horizontal velocity of 1.35 m/s.

After leaving the top it will follow the path of a half projectile with a horizontal velocity of 1.35 m/s.

It will traverse a vertical distance of s=85 cm=0.85 m under gravity.

We use the kinematics equation,

Initial vertical velocity u=0

This is the time to reach the ground

As we need to find out horizontal velocity we will only consider horizontal velocity and neglect vertical motion

It moves with horizontal velocity 1.35 m/s for 0.42 s

So, horizontal distance traversed is