# What was the cat's speed when it slid off the table?

• moshilover
In summary, the conversation discusses two scenarios involving an object falling from a height and striking the ground. The first scenario involves an autographed baseball rolling off a desk and the second scenario involves a cat sliding off a table while chasing a mouse. Both scenarios ask for the initial speed of the object before it falls. The formula Vf^2=Vi^2+2ad is used to solve for the initial velocity, but there is confusion about which distance to use in the equation. The conversation ends with suggestions to look at the vertical and horizontal directions separately and consider the acceleration in each direction.

#### moshilover

1. An autographed baseball rolls off of a 1.4 m high desk and strikes the floor 0.42 m away fro mthe desk.
The acceleration of gravity is 9.81 m/s^2/ What was the cat's speed when it slid off the table? Anser in units of m/s.

Since you want to find the initial velocity I used the formula:
Vf^2=Vi^2+2ad I wasnt sure which distance to plug in there (1.4 or .42) I tried both distances and my answer was still wrong each time. You plug 9.81 as your 'a', your final velocity is 0 and you try to find your 'Vi'.
So my equation is like this: 0^2=Vi^2+2x9.81x1.4 (or .42??)

2. A cat chases a mouse across a 1.7 m high table. The mouse steps out of the way, and the cat slides off the table and strikes the floor 1.5m fro mthe edge of the table.
The acceleration of gravity is 9.81 m/s^2. What was the cat's speed when it slid off the table? Answer in units of m/s/

I tried to solve this one with the same equation I tried to solve the first one with, I also didnt know which distance to plug in and both my answers were wrong.

moshilover said:
1. An autographed baseball rolls off of a 1.4 m high desk and strikes the floor 0.42 m away fro mthe desk.
The acceleration of gravity is 9.81 m/s^2/ What was the cat's speed when it slid off the table? Anser in units of m/s.

Since you want to find the initial velocity I used the formula:
Vf^2=Vi^2+2ad I wasnt sure which distance to plug in there (1.4 or .42) I tried both distances and my answer was still wrong each time. You plug 9.81 as your 'a', your final velocity is 0 and you try to find your 'Vi'.
So my equation is like this: 0^2=Vi^2+2x9.81x1.4 (or .42??)

2. A cat chases a mouse across a 1.7 m high table. The mouse steps out of the way, and the cat slides off the table and strikes the floor 1.5m fro mthe edge of the table.
The acceleration of gravity is 9.81 m/s^2. What was the cat's speed when it slid off the table? Answer in units of m/s/

I tried to solve this one with the same equation I tried to solve the first one with, I also didnt know which distance to plug in and both my answers were wrong.
You should look in the vertcal and horizontal directions separately, and note that the final speed of the object is NOT zero just before it strikes the ground. Try solving for the time it takes the object to hit teh ground by looking in the vertical direction only, where the initial vertical speed is 0, since the object leaves the table horizontally, and gravity is acting downward. Then look in the horizontal direction. What is the acceleration in the horizontal direction?

autographed baseball! 